Customization on WHMCS as per IDev affiliate software directions

We are a Hosting company and use WHMCS for billing, we are going with Idev affiliate software to sell our product and services through Affiliates, Problem with WHMCS and IDEV is, when you have an multy commission amount for multy product it will not work because commission can not be defined on cart value. To get this thing work, some changes required in WHMCS in commission processing file, IDEV will provide with the documentation at what needs to be done, you need to understand and have to done the changes accordingly. Pleas respond if you have the knowledge of WHMCS and have an some understanding of Affiliiates commission