PHP-Fusion Mod for Affiliate Code

I need a small mod to PHP-Fusion ([login to view URL]) (open source content management system using PHP/MYSQL). I have an affiliate program on my regular shopping cart site, and I link to my shopping cart site from various PHP-Fusion sites. I need to be able to enter affiliate id on the PHP sites, such as [login to view URL] That needs to be saved in a Session Variable and a cookie. This should work from any page inside PHP Fusion, so they might actually go to [login to view URL] or any ohter page. The purpose of the cookie is to remember the Affiliate ID, so that if someone returns to that site without the Affiliate ID, it will reset the Session Variable from the cookie. Then I also need a simple echo example how to build the link to my shopping cart site by using the session variable, example: [login to view URL] where x is the value of the Session Variable. I'm assuming if you bid on this you already know PHP-Fusion - I can't pay your time to to learn it. What I expect: You install and test on your own copy of PHP-Fusion on your site. When done, you zip and send me just the modified files. Make sure you document you changes with a comment that says something like: BEGIN-AFFILIATE-MODIFICATION-APRIL-2006 followed by END-AFFILIATE-MODIFICATION-APRIL-2006. I'm not sure I even need to test it on your site, but I am willing to if you want.