Session var read by form C++ CGI prog ?

I need to use something like a session variable to make a variable available to an existing form-invoked C++ program which takes as input a file being uploaded. Is this even do-able ?? If so, what am I missing here ??? The C++ prog used to use the REMOTE_USER env var set by the web server but we are no longer doing authentication via the webserver itself, so this one does not get set, and I need to set something myself. The C++ prog would had been grabbing this by getenv("REMOTE_USER"). I was trying some php to set a session var 'UPATH' but the UPATH variable doesn't seem to be visible to MyCppProg.exe : --snip-- <?php $_SESSION['UPATH'] = 'foobar'; ?> <form enctype="multipart/form-data" action="MyCppProg.exe" method="post"> File to Upload: <input name="file" type="file"> <input type="submit" value="Send"> </form> --snip-- I am new to php, have been digging around on the web, and not making a lot of headway quickly enough, so I'm asking. Thanks, JB