Ok, first your MeshBauer needs a List of points where to go next.

This is what you will get with the appropriate Pathfinding system.

The "Bauer" should always target the next point in the list. If it is reached, the point should be deleted from the list, giving the "Bauer" the next point to go to.

In case of something special (e.g. movable obstacle), the "Bauer" should react to it. This can be done by stopping and calculating a new way depending on the current situation (clear waypoint list and create the new entrys with your pathfinding algorithm again).

Thats just theory.. the pathfinding itself still needs to be done here. Maybe someone else can help here better than me (I could use this, too!).

Firle, the demo I linked has an EXE included. Just take a look at it to get an idea on how to use sensors on movable objects. I didn't take a look at the code, too, but I got ideas from the demo. The units will move much more realistic because the way isn't precalculated and the unit itself has to decide what to do when obstacles are in their way.