This would probably mean removing your player and replacing it with an AI that follows the target. I'm fairly certain you can't just use setMoveObject on a non-AI player.
But that can't be right- because we have mods like the one that makes movement macros. If you can make a script that makes your player do a bunch of different movements, why can't you make one that makes your player go towards another player?
This would be nice as events for bots, and is pretty much possible.