rem ...
rem      I run this batch1.bat
ren      some staff happens
rem      then I call bat2.bat with this content:

"%~dp0..x64app.exe" --u-language en --priority higher --output "E:[0] folder 13my file [00x00] block.mp3" --compression 3 --default-track 1 --und-uid "C:Tempkl45.45"

rem      this runs in a batch1.bat window
rem ...
rem ...
rem      script continues with lots of other stuff
rem ...
rem ...
rem      and here I would need to make a variable %varX% from
rem      "E:[0] folder 13my file [00x00] block.mp3"
rem      pls note that with those "" and use that %varX% below

"%~dp0..x64app2.exe" --input %~dp0..ghSOURCE.jpg" --input2 %varX% --output "%~dp0..filesID.vfxd"