ABIGLONE: there are 2 ways, either you make a spell based on slow orb or fire orb or whatever and chenge the target attachment to the model you want to attach, then put that spell on the unit you want to have the weapon, or an item if you want them to be able to drop that. the attachment point can be changed to weapon, head, overhead, left arm, torso, etc, depending on where the attachment goes. the second way is to create a trigger that fires during map initialization with "Create Special Effect on Unit" and set it on the "weapon" of the desired unit. thats one helluva description so i hope it helps...
anyway great model, although there is too much detail, try to cut down next time

4/5