revtex

Ok, Im not sure if that title is what I want... so this is what im trying to do.. I wanna beable to join my computer to my domain using a RunOnceEx entry.. I have tried but it dont seem to work.. I have read on the forum that other people have tried this with no luck.. something about the network not being 100% up at this phase of the boot. if this is the case, can I start services before the join domain command and bring up that network function?