Adding hack for existing subs?

[FordMustang]

Hey all,

I am wondering if there is a hack that will allow me to give a code or something to my existing paid subscribers so that they can get into the forums and view our online magazine. We have to separate areas, a "registered user" and a "subscription" area. I have 4,000 people who already paid their money for our paper magazine and need to get on the site to view the new digital one. To have to enter 4,000 names seems nuts.

I'd rather have a hack that would allow me to send them a code (alpha/numeric?) so they can go to the sub page in their user cp and put that code in and get in.

I still need my new subscribers to go to the sub area and pay.

Ideas?

Here is the site:

http://legendaryfordmagazine.com