Your challenge, if you choose to accept it, is finding some way for a state that is either Greek or Macedonian, descended from them, or culturally somewhat similar to them, to invade and hold a part of China for any length of time. By "China" I mean the core Han areas that have the most population. Any state from any period, or even an AH state, would work, though I suppose a Greco-Bactria would work especially well for this purpose.