Hi KapnKluck,
Welcome to Laptop GPS World.
My first guess is that it may not be possible to achieve it technically, and it may even possibly be against the licensing agreement of ALK CoPilot product. It may be much simpler to just buy ALK CoPilot Laptop 9, if you can find a source that still carries the old version. Version 9 is a few years old now, so the price will likely be quite low.
I'm just curious, what on board computer do you have in the motorhome? Is it something that was originally built into the dashboard, or is it something you built? Is it a Windows PC?