I have no idea:
The only options I see for your Azalia HDA controller is 'Auto' or 'Disabled".
1- does the rear output silence when a device is plugged into the front speaker/headphone output jack?
If so the only way I could guess would be to jumper the circuit through a disconnect switch for the rear jack so that circuit can stay closed when a device is plugged into it. Then I guess you'll need a disconnect switch on front if you don't want to unplug it, but either way it will take hands on.
Hope this helps a tad. Hope you get it figured out.