"Force target" meaning, selecting the unit ?! :S
I don't know if that is possible. I havn't seen it in any prominent maps where it would be beneficial. Such as Uther party, castle wars, ect.
Maybe when you say go, a countdown timer starts, displaying to all players
-SELECT YOUR UNIT-
-READY-
-SET-
-GO!-
Of course it's possible to select a unit for a player...
Trigger:
- Selection - Add (Last created unit) to selection for (Owner of (Last created unit))
Or...
Trigger:
- Selection - Select (Last created unit) for (Owner of (Last created unit))
Choose one