Can this powershell command be condensed any further? I want to try to speed this up. (One liners sent from a batch script)

*script updated below to reflect suggested changes

This is a CMD script my main question is for PS(But would def take cmd advice too, it is working though). It's using a powershell command as a one liner to "extract" an embedded files from itself. (When you drag/drop files onto it, it will embed them into itself, double click the script to extract the embedded files)

The extract command is slow.. I just updated this and it used to have temp files but I was able to get both variables I needed by switching groups with the same regex once for the first variable and again for the second, so maybe there's a way to get them both without searching through the entire file for each one?

(UPDATED 7/13/23)
Here is the full script BAG.cmd

@ECHO OFF & SET N=0
>nul 2>&1 REG ADD HKCU\Software\Classes\.Admin\shell\runas\command /f /ve /d "CMD /x /d /r SET \"f0=%%2\"& call \"%%2\" %%3"& SET _= %*
>nul 2>&1 FLTMC|| IF "%f0%" NEQ "%~f0" (CD.>"%temp%\runas.Admin" & START "%~n0" /high "%temp%\runas.Admin" "%~f0" "%_:"=""%" & EXIT /b)
>nul 2>&1 REG DELETE HKCU\Software\Classes\.Admin\ /f
>nul 2>&1 DEL %temp%\runas.Admin /f
FOR /F "usebackq skip=2 tokens=3-4" %%i IN (`REG QUERY "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v ProductName 2^>nul`) DO SET "VER=%%i %%j"
IF NOT "%VER%"=="Windows 10" ECHO. & ECHO UNSUPPORTED SYSTEM DETECTED! & ECHO. & PAUSE & EXIT
IF [%1]==[] (CALL :EMPTYBAG) ELSE (ECHO FILLING BAG... & ECHO. & FOR %%i IN (%*) DO (CALL :FILLBAG %%i))
IF %N%==1 (ECHO. & PAUSE & EXIT) ELSE (EXIT)
:FILLBAG
IF EXIST %1\* ECHO [Folder - Ignored] - %~nx1 - Folders are not supported! & SET N=1 & EXIT /b
IF %~z1 LSS 1 ECHO [File   - Ignored] - %~nx1 - Empty files are not supported! & SET N=1 & EXIT /b
IF %~z1 GEQ 750000000 ECHO [File   - Ignored] - %~nx1 - Not Added! The file is too large! & SET N=1 & EXIT /b
SET /A Size=(%~z0 + %~z1) * (130 / 100)
IF %Size% GEQ 980000000 ECHO [File   - Ignored] - %~nx1 - Not Added! There is not enough room in the BAG! & SET N=1 & EXIT /b
ECHO.>>"%~f0" & POWERSHELL -nop -c "Add-Content '%~f0' "^""::%~nx1::"^"" -NoNewline; [Convert]::ToBase64String([IO.File]::ReadAllBytes("^""%~1"^"")) | Add-Content "^""%~f0"^"" -NoNewline; Add-Content '%~f0' "^""::%~nx1::"^"" -NoNewline" & DEL /F "%~1">nul
EXIT /b
:EMPTYBAG
IF %~z0 LSS 2205 ECHO The BAG is already empty, drag-and-drop something onto the BAG to put it inside. ;^) & ECHO. & PAUSE & EXIT /b
IF %~z0 GEQ 80000000 (ECHO EMPTYING BAG... ^(This may take a while^)) ELSE (ECHO EMPTYING BAG...)
POWERSHELL -nop -c "$file=Get-Content '%~f0'; $match=[regex]::Matches($file,'::([^^:]+)::(.+?)::\1::') | Foreach-Object {$name=$_.Groups[1].Value; $fname=$name; while(Test-Path -Path "^""%~dp0$fname"^"") { $n++; $fname="^""($n)$name"^"" }; $data=$_.Groups[2].Value; [IO.File]::WriteAllBytes("^""$fname"^"", [Convert]::FromBase64String($data))}; (Get-Content '%~f0' -TotalCount 22) | Set-Content '%~f0'">nul
EXIT /b

The original line that took such a long time was the extraction command (updated above):

POWERSHELL -nop -c $file=Get-Content '%~f0'; $name=[regex]::Match^($file,'\:\:^([^^^\:]+^)\:\:^(.+?^)\:\:\1\:\:'^).Groups[1].Value.Replace^('::',''^).Trim^(^); $data=[regex]::Match^($file,'\:\:^([^^^\:]+^)\:\:^(.+?^)\:\:\1\:\:'^).Groups[2].Value.Replace^('::',''^).Trim^(^); [IO.File]::WriteAllBytes(\"$name\", [Convert]::FromBase64String($data)); ^(get-content '%~f0' -totalcount 26^) ^| set-content '%~dp0emptyBAG.cmd' >nul

Embedding/Converting to B64 happens very quick, but extracting/converting back to whatever it was takes a while.

Ive tested up to 1gb file with this script, only takes about 30 seconds to embed, but that takes 7-8min to extract ;P

Probably a good size for a test case would be ~40mb to see the delay but not have it be too long.

I think I am rolling through the entire file 4 times during the extraction command, 1) to set the file to a var with Get-Content, 2) to scan the var for the first regex to set $name, 3) to scan the var for the second regex to set $data, and 4) to stream out the $data named $name to create the final file..

I dont know how to make it more efficient =/

**EDIT - Script is working properly now(updated above), TY to all who helped.

The original line I was working on was

POWERSHELL -nop -c $file=Get-Content '%~f0'; $name=[regex]::Match^($file,'\:\:^([^^^\:]+^)\:\:^(.+?^)\:\:\1\:\:'^).Groups[1].Value.Replace^('::',''^).Trim^(^); $data=[regex]::Match^($file,'\:\:^([^^^\:]+^)\:\:^(.+?^)\:\:\1\:\:'^).Groups[2].Value.Replace^('::',''^).Trim^(^); [IO.File]::WriteAllBytes(\"$name\", [Convert]::FromBase64String($data)); ^(get-content '%~f0' -totalcount 26^) ^| set-content '%~dp0emptyBAG.cmd' >nul

There were unnecessary escape chars because I could use """ in place of \" in the powershell commands to get the same effect and enclose the entire line in ". Doing this allowed me to remove the redundant ^ chars. Leaving me with this:

POWERSHELL -nop -c $file=Get-Content '%~f0'; $name=[regex]::Match($file,'\:\:([^^\:]+)\:\:(.+?)\:\:\1\:\:').Groups[1].Value.Replace^('::','').Trim(); $data=[regex]::Match($file,'\:\:([^^\:]+)\:\:(.+?)\:\:\1\:\:').Groups[2].Value.Replace('::','').Trim(); [IO.File]::WriteAllBytes("""$name""", [Convert]::FromBase64String($data)); (get-content '%~f0' -totalcount 26) | set-content '%~dp0emptyBAG.cmd'" >nul

With the line cleaned up and easier to work with the regex was changed from running twice to running once and being referenced by var:

POWERSHELL -nop -c $file=Get-Content '%~f0'; $match=[regex]::Match($file,'\:\:([^^\:]+)\:\:(.+?)\:\:\1\:\:'); $name = $match.Groups[1].Value.Replace^('::','').Trim(); $data = $match.Groups[2].Value.Replace('::','').Trim(); [IO.File]::WriteAllBytes("""$name""", [Convert]::FromBase64String($data)); (get-content '%~f0' -totalcount 26) | set-content '%~dp0emptyBAG.cmd'" >nul

But what would happen if the regex found multiple matches? At this point it would cycle through and stop after the first. So in order to use the same command but continue through all the matches the "Match" command was switched to "Matches" and a Foreach loop was used to cycle through each object, using $_ as the current object. (along with removing the trim statements due to better data input and changing the outfile name and totalcount # because the script is smaller/less lines now)

POWERSHELL -nop -c "$file=Get-Content '%~f0'; $match=[regex]::Matches($file,'\:\:([^^\:]+)\:\:(.+?)\:\:\1\:\:') | Foreach-Object {$name=$_.Groups[1].Value; $data=$_.Groups[2].Value; [IO.File]::WriteAllBytes("""$name""", [Convert]::FromBase64String($data))}; (Get-Content '%~f0' -TotalCount 17) | Set-Content '%~f0'">nul

EDIT:
I was able to remove more escape chars, I didnt need them between the : in the regex, but the regex did require one.

POWERSHELL -nop -c "$file=Get-Content '%~f0'; $match=[regex]::Matches($file,'::([^^:]+)::(.+?)::\1::') | Foreach-Object {$name=$_.Groups[1].Value; $fname=$name; while(Test-Path -Path """%~dp0$fname""") { $n++; $fname="""($n)$name""" }; $data=$_.Groups[2].Value; [IO.File]::WriteAllBytes("""$fname""", [Convert]::FromBase64String($data))}; (Get-Content '%~f0' -TotalCount 22) | Set-Content '%~f0'">nul

Thank you all for your help!