Helicopter 'Instructor' autopilot

Hello panel designers everywhere,

I would like to build an xml autopilot for a helicopter that mimics the way an instructor hands the controls to a student pilot one at a time. I don't think I have to re-invent the wheel here as there are many autopilots out there but I would like some suggestions for APs that I can look at the code and learn what needs to be done to produce such an element.

Ultimately, it would control a hover and also be able to 'assist' the pilot on long flights as if control is handed over to a co-pilot.

It doesn't need to track any navigation devices like GPS or ADF, just hold IAS, heading and altitude in a cruise or hold a hover.

I do have an AP designed for helicopters but it is a .gua so I can't crib the code and learn from it.

So, if this doesn't already exist, does anyone know of an XML guage that would be the best place to start?

Thank you in advance,