AMEMBER+Drupal Coupon function(repost)

Currently AMember allows users to pay to register to the site. AMember also asign them a ROLE in Drupal by writing to the Users_role table. I need AMEMBER customized to react to COUPON CODES by placing the user into specific Organic-Groups associated with that coupon code. So that means writing to one additional table. The site is in DRUPAL. Once AMember is customized to react to coupon codes in this manner, I can go in and change the logic to react to different coupons and different OrganicGroup assignments.