If you go with IT2010 option, you get easy to valuate the wage type based on different criteria (based on personnel area, sub area, EE group, EE sub group, pay scale type and lot many decision criteria).
Please visit x015 and V_512W_B table once.
Regarding the dynamic action, theoretically, what ever you do at front end manually, that is what Dynamic action does on its own, so, if you are facing number format problem, try to enter manually once and see, how its being considered, try inputting different formats, until you are sure, its working for u, then implement the same format through your code.
You will be pretty good.
Warm Regards!
-Kanuku