your gonna have to use some triggers on that one..
Im not too sure on how to do it but i cant kinda outline it for you.
Just make the new trigger folder for your ability and then the trigger. Make a new event that an ability is being cast. Condition the ability being cast to that certain spell. Make some actions that raise your hero to a reasonable height and then drop him back down.
I dont know how to put it in triggers but there ya go.