Don't think you want to use a motion path (single start and end point), as you will need something that can branch out.
Kirupa has a tutorial for something that could be adapted to work for your project.

http://www.kirupa.com/developer/acti...ata_types3.htm

Or you could look at making something tile based.

Also you can try Google for flash as2 point and click engine to look for other solutions.

HTH