Add Affiliate Id As Hidden Field To Getresponse Form

Hi, I need for my affiliate id's to be placed inside of my getresponse optin form code in hidden field so that we may see the 'referral id' in getresponse for each subscriber. The affiliate link structure looks like this and the numbers at the end are the affiliate id's for each affiliate. [login to view URL] When the link is clicked it goes to a squeeze page where the getresponse form is. I want to have hidden value in the form that grabs the numbers at the end of the affiliate urls so that when people subscribe to our list it shows which affiliate referred them. [login to view URL] This should be done in 1 day and if you can do it you'll have more projects your way.