I think I know what you're talking about... here's how I used to do it.
I'd name the gallery page to index.php and put it in a seperate folder, then in the link... I'd add this piece of code:
<?echo $_REQUEST["ref"];?>
So, if I wanted to send a click from the gallery to the url of
http://www.bangingwhitey.com/tour1/ the actual linking url would look like this:
http://www.bangingwhitey.com/tour1/?<?echo $_REQUEST["ref"];?>
Now, tell your affiliates to send to a gallery url like this:
http://www.YOURGALLERYURL.com/foldername/?ref=CCBILL
I "think" that's the correct way. I'll check it in a little bit to make sure (unless someone else can spot an error).
Hope it helps...
- PornAddict