Trims buttons as transmitter channels

Hi, I am trying to use the two upper Right and Left Trims as separate transmitter channels, but do not know the way to do it. With the official firmware you can chose those two Trims as transmitters channels and I suppose it is also possible to do it with Deviation, but I do not find the way to do it. I appreciate any help about that.
Thanks and regards.

Solved. I have just seen it is possible to define one virtual channel with the value of zero and then add the trims. So, at the end by using that virtual channel in one transmitter channel it is possible to use those trims as transmitter channels. Perfect.