object following bone?

OK, so I just posted a post asking about a way to make a particular bone on an entire armature follow the mouse…
I wish to throw another curve ball in the ring…
How would you make a bone follow (track) another object in the scene?
I have tried creating a “track to” constraint on the particular bone I wish to track the object…but it has no effect at all in the GE preview mode…

SOmebody? anybody?
COuld you shed light on my desire to have a bone track a moving object in a scene of a game?
In advance…thankyou for being a lifesaver!

You could possibly use 2 bones. One animated on the x and the other on the y. Then you could control them with action actuators setup in property mode. Unfortunately, there is no way to get around python scripting for the mouse.

Could you please make a little example demo? Thank you.