i dont think so because you will have no fixpoint in depth for the target. you can script the scene using playerspeach and waypoints to go on keypressed-commands, but thats an automated way and not the same.
normally AI reacts on noiseheard-commands, but i dont think it will work when firing a grenade to the place where you want him to go, this normally doesnt work on friendly fire. but you can try.
setup a friendly darkAI in an area without enemies and throw a grenade and see if he follows.
if it works, you can setup a grenade-gun with altered sound (blip) and model (lets say a flare) to get the background.