External member discount code implementation

[spmckee]

By "clone" of an order-total module, I mean to make a duplicate copy of the corresponding PHP files and then customize the PHP code and language strings in them to suit your needs.

OK, I've made copies of both the "ot_coupon.php" module and language files and named them uniquely. I have also renamed the "ot_coupon" class and changed the naming on the language constants as well. However, I've looked and looked but can't find where to include/call the newly made files. In which PHP file do I call them up?

Thanks!
SP