Paypal Subscription

I have an existing Paypal Standard business account and web based payment system set-up for an Indie, online MMORPG game called Blood Clans. [[login to view URL]][1]? The game is currently closed and being recreated in a new game engine. In the current set-up players can buy game money with real money. We use an IPN to notify us via email and to add the game money to the players account in our MS SQL database. Now, I want to add the monthly subscription feature and assign a Citizen number to the players account in the database. It would include setting up a very simple subscription page with? a button, the IPN and the routine to add an account number in order starting with 000001 to the players account information in the MS SQL database. As each new player signs up they would get the next account number in line and a status flag would be set to Active. Also, an unsubscribe button that would remove the status flag but not the number and, of course, would end their subscription thru Paypal.