Isolating Sounds ATC Sounds specifically)

I have a need to direct the ATC sounds (Comms, ATIS) to a separate channel/System/feed...

I am using a G/A 4-place Aircraft headphone adapter and need to feed ATC comms into it via the 'Music' input.
That means I somehow need to isolate the voices in X-Plane (Not the voices in my head, they never shut up!) to send it to the 4-place adapter.

Some roads I've traveled:

1. Setting up a slave X-Plane computer to play just the COMMS.  

2. Running the X-PLane Audio through a software bypass filter to isolate voice and send to alternate source

3. Slave an iPad to the main X-Plane box and feed the iPad audio to the adapter.

Anyone ever done this?