Hey Ryan, thanks for your really quick response, I had actually come across that page but was hoping that there might have been some module made where I put in a URL for the bank and create some expected variables to send and receive.

How would you suggest going about using those functions? I envisage creating a module which is invoked when going to a specific URL but haven't mastered this yet. Can a module specify its URL? Can it somehow tell drupal to call itself on a specific URL?

I intend to release this if I do create a module and love the work and support you guys provide, we are seriously looking into donating on a per website basis so thanks for everything so far!