I planning to use Zen cart, and would like to create new payment module using my bank service for online payment in local CCY to avoid FX on buyer.

the payment gateway would work as follow (XYZ gatway)
- Buyer chose payment gatway XYZ
- Buyer will be diverted to XYZ website (site will get all order amounts and reference numbers detail via POST function including the return URL)
- Buyer will excute the payment at XYZ website
- XYZ will return back to Zen cart with transaction response on URL in which we can use $_GET to have the transaction execution result. and insert

would appreciate your help how to start developing such module, and how zen should work with it