Picking up item transform unit and then goes back. HELP

I need help on how to do this.

When a hero picks up a certain item then it transform to a new unit that last only 30 seconds then goes back to the normal hero.

I dont want the hero to have the metamorphasis based spell on it. Anyway on how to do this.

NOTE:
I want this to work with 7 different heros.

try this"

E: unit picks up an item
C: item manipulated equal to <item>
C: hero manipulating item equal to <hero>
A: replace unit blabla

but replacing units is waaay to bad....u need some spell like temp metamorphosis, and when u pick up the item it adds that ability and issues an order to activate it....

or even better
when the item is activated, it goes away(remove item, or give it 1 charge) add metamorphosis, issue the metamorphosis order, and remove metamorphosis....voila :)

Try to give the item a modiffied Storm Earth and fire spell that only summons a unit type, then make the item to automatically use when acquired

Just a guess... but would giving the item a Metamorph ability and then making the item an "Auto use" type (Pick it up and it automatically uses it) work?


EDIT: LOL disregard my post, I just realized I said the same thing as Vex did...

I'll try that