Hi,
Your question is a bit confusing to me, but for what I understood, this is what I do:
First, I right-click on the banner of the GPT site, and download it to my harddisk.
Then, I upload it to my website as an image.
Finally, I right-click on the banner which is on my website now, I click 'properties' and then I can see the url of the banner.
It's this url that I use to send to the webmaster for my advertising:
I write for example:
banner:
http://www.cashsite.nl/inc/img/homepages/u...snslkpbqygs.gif(which is on my website)
URL:
http://www.cashroyal.com/anneke (no, this is not an existing ref link)
(which is my referral link for this site)
I hope this helps.

LOL, I had to edit out the url link, I made something with xxxxxx, and it turned out to be an adult site.