RE: Trying to achieve. I'm doing a facial rig that have multiple pose morphs and multiple joints within that morphs. With controls that does not reside with its controlled joints. It's somewhat complicated. So the illustration file is really the clearest I can provide.
With your solution, when I scrub the timeline, the Cube moves. (That was the problem earlier. When I try to change something, any change, frame or a simple click, the cube moves. It should not).
It should only be incremented by an arbitrary amount (in this case 5). Regardless of what frame I am in.
So in your question,
Do you want A to increment by 5 only one time?
Yes, in one time only unless I change the arbitrary amount.
Is that possible?