Drupal module creation to use external Table

Project Budget (USD)

Project Description:
Project Description:
I guess this is just a simple module.
my current database table:
acCard : contain member information and bonus point info
acProduct: contain product information

I want the users of my current acCard table on the server to be able to login into my Drupal site.
I don't want to migrate the current users to Drupal, because I need the same database for different things.
also need the bonus point feature.

I want the product sold in website can select from acProduct table and update its quantity.

Skills required:
Drupal, eCommerce, PHP
Project offered by: