Is there any possibility I can override the mechanism of "Apply Promo Code" with my own ? I want to integrate a loyalty system and I want to use the same Apply Promo Code process. I could not find any hook for this process. If there is none, Would I be able to hide the apply promo code box using any option of I must edit the .tpl file ?
For example, use Gift Certificates module as example. It alters default Promo code functionality and adds ability to apply gift certificates and promo codes in one field