I am planning on taking payments via eChecks, so I installed the Instant eCheck module. I was wondering if I could edit this module to work with my eCheck cashing vendor which is Global Payment. I did a search of my files for anything to do with eCheck looking for the right PHP page to edit but didn't find anything. I'm new to this so any help is greatly appreciated. Thanks.

Zen Cart 1.3.8a
Patch: 1::
Database Patch Level 1.3.8