This seems to be impossible for me,
if you like being a passenger in a cockpit 
You may want to create a flightplan in direct/GPS mode and set all points you want to fly above.
Then start the flight and take-off manually.
But please don't use ATC as it would nerve you all the time then! Just take off.
Now set that switch somewhere in your cockpit from NAV to GPS if it isn't yet,
start autopilot with the altitude you wish, and select that button , that's called I think "NAV" (but I'm not sure).
It should then fly the trip you can see when opening GPS.

Note that the plane will just fly straight forward after the last point/ landing aiport is done.
It does not land automaticly!

Hope this helps, even if you have to start by hand and don't have a pasengers cabin.

rev