Switch midi input from keyboard between two organteq manuals

Hi all,
I have two midi keyboards and instead of buying the third one (for each of organteq manuals) I would prefer a possibility to switch the output from one keyboard between two manuals (swell/positiv for example). Although I can change midi channel on keyboard, it is just possible by using two hands and it takes too much time. I tried to find some midi channel converter to do this with one click, but didn´t found nothing cheaper than buying third keyboard. Maybe this could be implemented within organteq, to switch input from one midi channel (keyboard)  between two organteq manuals by using for example one of the keys of the PC keyboard, or assigned midi input (from launchpad, toe piston, sustain pedal, virtual button on touchscreen or one key of midi keyboard...). Or is it allready possible?  Thank for Your comments and ideas. Maybe this could be useful also for people who have hardware organ consoles with two manuals