c:\>set pathext
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.py;.pyw

c:\>set pathext=.pl;%pathext%

c:\>set pathext
PATHEXT=.pl;.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.py;.pyw

c:\>script.pl > noperl.txt

c:\>type noperl.txt