Pass affiliate ID into submission form

I am using affiliate pro. My new customers fill out a form to receive a free trial with us (we currently use either contact form 7 or formidablepro) and we are setting up affiliates. My problem is that I need the form notification that is sent out after the new customer submits it to include the affiliate id or token that referred them to my website. In short, I basically have a form on my site and I need to know how to pass the affiliate ID into it automatically. Thanks