Custom Proxy

I work for a credit card company. Our card is issued through a bank - we are a co-branded card. In order to apply for the card, the applicant is directed to the bank's website which is on a secure server. One of the fields on the application (about three pages in) is called "Affiliate Code." Ordinarily, the applicant needs to enter this code manually. Our goal is to create a "proxy" which will pass a variable from a third-party banner to a "proxy" server. The proxy will autofill the affiliate code field based on which banner the applicant clicked. ## Deliverables * The IP address of the user needs to be passed on to the bank, so that they can track who is applying and so that it doesn't appear like all these applications are coming from our own server. <!-- --> * We have no access to the bank's coding and can make no changes on their end. Instructions: 1. Go to [login to view URL] 2. Click "apply now" in the text links at the bottom of the page 3. In the "Online" section, click "Signature" 4. That will take you to the US Bank application page - click "apply now" on their page. 5. Select "Individual", expand the "Terms and Conditions", check the "accept" box 6. Click "Continue" * The first field on this page is "Affiliate Code" * We want to automatically fill in this field depending on which banner they click on to initially get to the application page. * Furthermore, we want the bank's servers to "see" the user's IP address, etc. so they don't think every application is coming from our IP which would trigger a fraud alert. Also, it's important that they get this information for tracking and demographics data, so we want our server to be as "transparent" as possible. The above is how customers apply directly from our site. Our Goal: We would like to put banners on third-party websites. When they click on the banner, it will take them to a landing page on our website. When they click apply now, it will then take them to the US Bank website where they can apply. When they get to the screen that has the affiliate code, the code should be autofilled based on which banner they clicked (we'll assign a code to each banner). They will fill out the rest of the form themselves and submit it themselves, etc. My thought was to create a custom proxy script in PHP and run it off our own server. The challenge is that US Bank won't make any changes on their end. We are open to other suggestions to accomplish our goals.