omg.... u use the models as attachments. You can make a hero start out with them at default (best for triggers) or else use them when a hero picks up an item (a weapon) and then the hero "weilds" it. (best to use buffs)
Either with the trigger Special effect - create speacial effect on unit. And then type hand where you can write where to put it. Or you can use an aura or sphere kinda like. Instead of attaching to "origin" you attach it to "hand".