I'd like to take the value of a two-part revision variable (A.02, B.03, etc.) and place just the Alpha part into a separate card variable, and do it automatically.

I've looked into using an input formula, but it seems that these formulas only calculate when the user manually types values into the source variable field, not when a variable is updated by the system, for instance upon a state change.

Next, I thought I'd look at Dispatch, but I need to read the source variable, then write a modified version of it to the destination variable, and although Dispatch has a Set Card Variable command, it apparently doesn't have a Get Card Variable command, which seems to me a glaring omission.

Need I write an add-in for this seemingly simple task?