TOPIC: Backend Invoice

We have a system which manages invoices and posts payments. We would like to only show the total and current due in DT Billing to allow some of our members to pay online.

Once a month we will replace the amounts in DT Billing from our back end system.

We also want to show the payment methods Visa, Master Card and American Express with a specific uplift percentage and add the uplift when we process the charge.

Is there a way to do this, hacks are ok.