I'm going over all of the information again and I see what I was refering to is their IPN (instant payment notification) script. What this cgi script does is update an .htaccess file so that subscribers are instantly added to the calling site's subscription area. What I want to create is a php script that would follow through on their authentication from paypal and then adjust what ever in the .threads user's table.
Have you created such a script or is the IPN not something you were going to impliment?