Connecting through telem2 in SITL

I am working on an application running on a companion computer. In the real thing, this application receives telemetry data from pixhawk (they are connected through a USB cable connected to the Telem2 port), and sends commands (eg: change flight mode) the same way.
This is working as intended. What I can’t seem to figure out is how to do the same in SITL?

I am sorry for starting this thread: just found the answer in
For anyone else interested, adding the arguments
-A "–uartC=uart:/dev/ttyS7"
when running did the job (in this case it’s connection telem2 to COM8)