I'm integrating Zen Cart into my own CMS and I have a need to call a custom function when an order is successfully placed. The basic Idea is I'm selling "points" that can then be redeemed for merchandise.
When an order for points is placed, I want to call a custom function that inserts the number of points purchased into another database table.
My question is, which particular file should I be working with to place my function call? Zen Cart is new to me and I'm still struggling to find my way around in the code.