Spell Redirection

[The Howling Storm]

Greetings, GUI user here. I am attempting to create a spell that redirects attacks and spells from the target to the caster. However, the GUI does not have the capability to redirect *any* ability, even if that ability is set to a variable - at least, my search for such has not yielded results. For now, the best I can do is simply give the target unit spell immunity, but I would be greatly appreciative if anyone could find or write a function, either Jass or GUI, that would allow me to either change the target of the spell itself, change the target of the order, or issue a new order to cast the ability upon the intended unit.