Syncing target gameobjects over a network

Hey Guys,

Im making a LAN networking game and just having a slow day it seems as I can think of the most efficient way of syncing a target game object over the network.

Example: Clients flying ships and one wants to designate a primary target out of multiple targets. Because I can't send game objects RPCs over the network whats the best way of doing this?

Cheers
Terry