Excel - find a line based on the contents of a cell and copy content from another cell in that line to another cell in another line

I have some experience in front end development, but now I'm trying to find a solution for a situation I'm having in Excel. Let's say I have the following example of a spreadsheet:

The table is not looking as I expected so here's a picture:
table

As you can see, the products with ID aaaaa and bbbbb appear two times each in the spreadsheet (always in Col.A). One time they have no characteristics (empty Col.B and Col.C in lines 1 and 3), but the second time, they do have some characteristics.
I need to copy those characteristics (from Col.B and Col.C of line 5 and 6) to Col.B and Col.C of lines 1 and 3.

Of course, I cannot copy them manually because the table has over 1500 lines and they are not in order. It has other lines between the ones I need, like Line.2 with zzzzz which needs to stay as it is.

I'm thinking of somehow identifying the line by using the product id and then copy Col.B and Col.C from the line where it's found to the line where I need it. Something like:
if aaaaa is found & Col.B & Col.C are not empty, copy Col.B and Col.C from that line to the line where aaaa is found & Col.A & Col.C are empty, but I don't know how to make this in Excel.
But there probably are some better solutions, anyway...

Thank you!

I would use your solution. To achieve this you first have to make a lookup table with no blank values.

then make a formula that has a IFBLANK and a VLOOKUP function that looks up the value if a blank value is found.

i wrap this in an IFERROR in order to see that a certain value is not found in your Lookup table.

Formula in cell E3:

=IFERROR(IF(ISBLANK(C3);VLOOKUP(B3;$K$3:$M$4;2;FALSE);C3);"NO VALUE FOUND")

Formula in cell F3:

=IFERROR(IF(ISBLANK(D3);VLOOKUP(B3;$K$3:$M$4;3;FALSE);D3);"NO VALUE FOUND")