Custom heros using custom spells

First off, I tried to use the search, but it seems the AI section has been nuked due to the update.

I'm currently working on another version of Battle of the Gods, and in this new version, I want any unused slots to be controlled by the computer. I want a custom hero to pick, a path, run down it and fight, and decide which custom spell to use and when to use it. I think I can do most of it with some extensive 'if' statements, but i've reached an impass which I can't seem to get around.

While it's easy to get a hero to learn a custom spell, having him use it is a different story. I need to know how to make a hero use a custom spell via triggers, jass, or whatnot. I prefer triggers, but will gladly take jass.

If you know how to make a hero controlled by a computer unit cast a custom spell on a triggered command, please share with me what that command is.

Thx in advance.

Order the hero to use the spell the ability was based from (unless the special ability is channel and you changed its orderid, in that case use that orderid)

Thanks, that will help a ton..