Move a little dot along a dial. Suggestions?

Hi everyone, I am trying to make an interaction with a dial but it has this feature: I want the user to move the red dot along the grey arc, starting from zero, and when the dot reaches certain position, shows certain content. I will try with a dial with many values, so moving the pointer creates the illusion that you are moving the dot softly (see pictures).

But before trying (which will need many triggers and states, I think) I wonder if any Storyline wizard would try a simpler method, or perhaps a tool different from a dial. Thanks in advance, I´ll appreciate any ideas.

Daniel Albarrán