Mount Action: How to do more than retract via RC channel


I have successfully connected my Storm32 gimbal via MAVLink and if I go to the MP Action Tab I can select RC Targeting, press “Set Mount” and it works with the RC channels selected for the relevant axis on the gimbal. I did make use of RC option 27 to retract the mount which does reset the gimbal to start up position. I can however not find a way to set the mount/gimbal to RC Targeting via an RC Option. Is there a way to do this in other ways within Arducopter to toggle between for example Set Mount Neutral / Set Mount RC Targetting via a RC channel ?

Kind Regards
Jan P