Implementing an Affiliate TrackingCode

Hi,

I should implemtent a tracking code from an affiliate network. The code has to be implemented in the code of the site which appears after a successful donation. I guess it's the "Donation Completed"-site. In the tracking code I also has to insert two variables. One which contents the user name of the donator and one which contents the donated amount.

Can you name me please the name of the file and the variables?

Thanks, Alex