How to use one controller for the drone and one controller for the gimbal

I want to use a controller to control the gimbal. There is no problem for this. But if i want to use a second controller to control the drone, is it possible ? I mean, I’m getting the values for the gimbal throught RC Channels :
So in my gimbal, i’m requesting the message : RC_CHANNELS and i can get these value to control the gimbal. I can also use the buttons for the gimbal.

But my question is here: if i want to connect another joystick for the control of the drone, how can i do that ?
Thank you

use a program called Vjoy to make a custom virtual joystick that you can assign inputs to.