If it's not using the arrows you probably need a script that creates them. If a projectile spawner is included with his ABS, I'd suggest asking blizz himself how to use it or how to make one. Also, if it does have a projectile shooter, (I vaguely remember trying that ABS) you're probably missing a command between making your character do a shoot animation and actually spawning an arrow.
EDIT: Ya, I haven't touched this ABS since last year, and behold, as nam points out it has a manual -_-
Indeed, ur missing an arrow charset.