Product Allocation (PAL) of the advanced ATP in S/4HANA OP1610 needs a semicolon delimited CSV file for a upload and download planned PAL data.
If you doesn’t use an European language Windows, it is difficult to create and treat the semicolon delimited CSV file.
I stated how to adjust your Windows delimited character.
You can go Windows control panel> region > Formats > Additional Setting
Change the list separator from comma to semicolon.
Then you can create a semicolon delimited CSV with Excel CSV(comma) saving option and opening the semicolon delimited CSV file.