Payment Reference Field (from Shopify/Amazon)

Would like the Payment Reference Field to be customizable so that transactions can be reconciled in Quickbooks. 

Currently the Shopify Payment Reference # comes through, which isn't a number that is found anywhere (not in a Shopify Payment Reconciliation Report, etc.), so is useless.

Ideally, would like to be able to map what goes into this field. Primarily, the Shopify Order #.