comminucation from mavproxy to pi

senario : My pc which is connected to the Ground radio telemetry needs to send some messages say (hello) or on mavproxy commend (arm throttle) to the pixhawk telem 1,and on the pi which is connected to telem 2 , I need to receive these messages.
what I could do so far is :
Using mavproxy I can send some commends and the pixhawk will act on the commends , e.g arm throttle.(pixhawk port Telem 1 is connected to air radio telemetry).
I can also control the pixhawk using the pi , arm throttle ,... .( Pixhawk port Telem 2 is connected to the PI).
what I could not do is :
receiving the sended commends from mavproxy on the pi?
is there any body that can help to figure out this issue ?

The issue mentions MAVProxy, Pixhawk telemetry ports, and a Raspberry Pi but names no repository files, tests, or entry points. First clarify the expected message-routing behavior and the MAVLink telemetry topology; the work is done when commands sent through MAVProxy are reliably received on the Pi.

Written by the indexing model from the issue text.