Add Custom Expiration Timer to Unit w/o Death

Hi,
I need the Add Expiration Timer to Unit Trigger but I'd like to use a custom one. But the main problem is how to prevent the unit from dying after the timer expires. Can anyone help me?

Make a REAL timer, using variables. Just do a trigger saying that the timer expired then kill the unit manually. Expiration timers are meant to do what they say they do.

I think he wants to show a duration bar in the unit during the effect of a spell, I think it is plain impossible