@setlocal
@set thisdir=%~dp0
@set thisfile=%~f0
@set thisfilebasename=%~n0
@set thisfilename=%~nx0
@set thisfilecorion=%~dpn0.pl
@set thisfilepl=%thisdir%%thisfilebasename%.pl
@echo          thisdir=%thisdir%
@echo         thisfile=%thisfile%
@echo thisfilebasename=%thisfilebasename%
@echo     thisfilename=%thisfilename%
@echo   thisfilecorion=%thisfilecorion%
@echo       thisfilepl=%thisfilepl%
@echo;
@endlocal
[download]

         thisdir=D:\
        thisfile=D:\this2.bat
thisfilebasename=this2
    thisfilename=this2.bat
  thisfilecorion=D:\this2.pl
      thisfilepl=D:\this2.pl
[download]

And the advanced broken version (for stupid paths )
^ is trickier than the others ... above escaping useful for example if you're  echo %stuff% >> otherfile.bat
yes, cmd.exe is a mess

@setlocal
@set "thisdir=%~dp0"
@set "thisfile=%~f0"
@set "thisfilebasename=%~n0"
@set "thisfilename=%~nx0"
@set "thisfilecorion=%~dpn0.pl"
@set "thisfilepl=%thisdir%%thisfilebasename%.pl"
@echo          thisdir="%thisdir%         
@echo         thisfile="%thisfile%        
@echo thisfilebasename="%thisfilebasename%
@echo     thisfilename="%thisfilename%    
@echo   thisfilecorion="%thisfilecorion%  
@echo       thisfilepl="%thisfilepl%      
@echo;
@set "thisfile=%~f0"
echo %thisfile%
@set "thisfile=%thisfile:^=\^%"
@set "thisfile=%thisfile:>=^>%"
@set "thisfile=%thisfile:<=^<%"
@set "thisfile=%thisfile:&=^&%"
@set "thisfile=%thisfile:|=^|%"
@set "thisfile=%thisfile:)=^)%"
@set "thisfile=%thisfile:(=^(%"
@set "thisfile=%thisfile:[=^[%"
@set "thisfile=%thisfile:]=^]%"
@set "thisfile=%thisfile:"=\"%"
@echo escaped-thisfile "%thisfile%"
@echo;
@endlocal
[download]

$  "D:\pa^th\this2.bat"
         thisdir=D:\path\
        thisfile=D:\path\this2.bat
thisfilebasename=this2
    thisfilename=this2.bat
  thisfilecorion=D:\path\this2.pl
      thisfilepl=D:\path\this2.pl
[download]