Telex Radio Dispatch System Integration with Cisco Unified Communications. Part 1

I have Telex Radio Dispatch system I want to integrate with a Cisco phone system.

Side note: Using two Cisco UCS C-Servers with VMware. Cisco' UC on UCS. Works great!

Telex system has interfaces to the radio networks and the telephone network. 

Each user has a Telex ADHB-4.  This device mixes the audio from the different Radio networks and the telephone. Coming out of the ADHB-4 is a headset for the dispatcher. The dispatcher has a desktop application were they can select different audio sources and the ability to combine audio channels.

The interface between the phone needs audio tx and rx along with on/off hook switch and ground across 6-wires.  The box/application needs the hook switch to answer and hang up calls.

I am wondering if I can create a cable from the Phone to the Telex Device. Telex provides a basic diagram:

I would think I could get TX and RX audio and Ground from the phones headset port. I would also think I could get Hook Switch from the phones aux port (this is the port used for the wireless hook switch feature).

We will see how today goes, I am almost onsite.

I'll keep you posted.