Customer loyalty points system with integration

I have a sales system in a retail store that uses an MS Access database for all records. I want to create a customer loyalty points system that gives club members points for each purchase that they can redeem for future purchases. I need a program (in ms access or similar) to analyze the sales records, calculate the point status and usage. Then we need to integrate it to my sales system, where I can see the point status and usage for each member. If users could see their point usage and status online in their profile on our webpage (updated via cron every x hours) then that would be great. I currently use WP-Ecommerce for web sales. The project involves a little brainstorming on how to get this solved in the best possible way.