I've done some digging, and the scripts you want are under 'UNUSED', sub-directory 'units'. An example of the script is:
Unit 'Particle cannon #1' fire waypoint-weapon following waypoints starting at Waypoint Path 'PC fire path'.
with the unit name/waypoint path being whatever you call them. That should work (though I haven't tested them yet)
As for the tomahawks thing, I suspect they used some script to make them attack the scorpions as they approach rather than have them on auto guard. I'll go check it out and get back to you
*edit - dang, I've gone and bumped an old topic
Ah well...