On OziExplorer , you can project a waypointwhich will put a marker at the co-ordinates you have entered.
UTM is the easiest format to use, the Emergency Service Map Books are in UTM.
the UTM co-ordinates are also where your 6 digit rapid numbers come from (which I find heaps more useful than the new rural addressing system)
also, give Androzic a shot on android, I find it better than oziexplorer android, and its free..
What maps are you using?