UK compatibility without using the Gateway?

Hi folks,
Am in the UK and already have our own payment gateway installed.
We wish to use this plugin purely for back-end manual orders, and recording the possible multiple payments that pertain to any one order.

Any actual payment would be taken on a different screen, then the record of that payment entered into the ‘Woocommerce manual payment’ facility plugin, hopefully then would give details of that orders balance ect?
Am I seeing this as a working scenario, or possibly reading it incorrectly??

Any help would be very much appreciated, Thank you