I wanted to map everything "keyboard free" and with all those buttons I'm well on my way.  I've got a problem though.  If you go to Controls/buttons menu in FSX to get your mapping commands for each button, you can see "select heading bug", "Select altitude bug", and something similar for speed.

OK so you have them selected.  How to you map them to a wheel or dial to change the bug?  There are no key presses for this.  I don't understand how you could change your heading number, or altitude number, or speed number.