Copy files to enviroment variables path

Hi All.

is there a way to make the $INSTDIR point at a directory set by a windows environment variable say:
%windir%

Im new so nsis, so any help would be appricated...

regards

Karl

just answered my own question:

ReadEnvStr $R1 "WINDIR"
Setoutpath $R1
File "what ever files"

Use $WINDIR.