Make playnite can run batch command in x64 ( 64-bit paths ) environment

Playnite is 32-bit process and therefore can't natively access 64-bit paths, you'll get redirected to 32-bit counterparts instead. You'll need to use different paths, like in the picture below :

Fill path with :  C:\windows\sysnative\cmd.exe

Fill Arguments with : /c your_file.bat

Set Working Directory with : the directory of the your_file.bat