An custom ability question..

[Braindead]

Hi folks..

I played this map recently, it was a TD map (Natures call circle defence think it was..).. Anyhow, theres was a unit there, that had a custom ability (acctuarly I've seen this ability flash me by before..) that allowed you to atomatically teleport your unit across long dintances of the map (It was walking short distance)..

To my question, how would something like this be coded in the Warcraft III World Editor?