Relaying data from telem2 to telem1 in pixhawk


i have an embedded device that i am connecting to telem2 in my pixhawk. Using this device i want to relay data from telem2 to telem1 to the ground station i am using (QGroundcontrol). the messages i send are COMMAND_LONG and i use same source ID of the pixhawk so i dont need to emit a heartbeat, as target id i use the id of QGroundcontol.

the problem i am having is that this only works when i load firmware of ardupilot in in mission planner into the pixhawk, otherwise the messages are not passed from telem2 to telem1.
any ideas how can i solve this issue or, any other way i can relay data from telem2 to telem1?