How to change the language of Windows by a macro in excel?

I have created a form. It's name is FF and the form
is showed with a simple module:

sub SH()
FF.show=true 
End sub

This form contains some buttons and I have put shortcuts for these buttons with
the following codes:

CommandButton1.Accelerator = "H"
CommandButton2.Accelerator = "A"
Command...

If the language of Windows is English and I show the form,
the shortcuts work correctly, but if it is not English
and the form is shown, then the shortcuts does not work (even if I press the "Alt+leftShift").

So I have to press "Alt+leftShift" before I show the form.
But this can be forgettable and... .I think I shoud put some codes before "FF.show=true"
to change the language of windows to English. Is there any code that solve my problem?

Thank you for your help

Two languages are installed on my computer. I am using two Functions to change the keyboard through VB

Option Explicit
#If VBA7 Then
Private Declare PtrSafe Function ActivateKeyboardLayout Lib "user32" (ByVal HKL As LongPtr, ByVal flag As Long) As LongPtr
#Else
Private Declare Function ActivateKeyboardLayout Lib "user32.dll" (ByVal HKL As Long, flag As Long) As Long
#End If
Public Function ELLHNIKA() As Integer
   If ActivateKeyboardLayout(1032, 0) = 0 Then
      MsgBox ("Unable to select Greek keyboard")
      ELLHNIKA = -1
   Else
      ELLHNIKA = 0
   End If
End Function
Public Function ENGLISH() As Integer
   If ActivateKeyboardLayout(1033, 0) = 0 Then
      MsgBox ("Unable to select English keyboard")
      ENGLISH = -1
   Else
      ENGLISH = 0
   End If
End Function

If you want to switch between the installed languages then use this version:

Public Sub NextLang()
   Call ActivateKeyboardLayout(1, 0)
End Sub

https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-activatekeyboardlayout