Coreg System

Hi, I want a coreg system building into this website [login to view URL]%fre%[login to view URL] (remove percentages) what a coreg system is, is when someone joins and ticks a box for the coreg it submits there information to that offer. I want an admin where I can add coregs and they only appear for the specific country of that user so if the user selects United States then coregs for United States appear when they tick the box it then submits there information this offer in the background so it loads up the final page and it loads that url somewhere in the background so they can't see it happening. When adding a coreg I will specify the url to load in the backgrond and I need to be able to put tags in this url like [FIRSTNAME] which inserts there first name in the url and then loads this up in the background. Thanks a lot, Matt Lovett