Your best betfor a start will be to first learn how to animate a gauge at all. Then you will have a better shot at figuring out how to work in special conditions.
Many things you want to learn can be found using Google and some simple but direct search terms... "AS3 animated gauge tutorial" might find what you're looking for.
The basics of creating a gauge involve creating a needle movieclip that has its x/y registration at the pivot point, and then controlling the rotation property of that needle object.
Thanks I'll check out the search and see what I can find. I have built a Menu with a dial that animates a needle but this will be allot different then anything I've created in the past.