I am trying to plot two points in MGRS for Myrtle Beach, SC. As far as I can tell I need to set my data frame to NAD 83 UTM Zone 17S.I cannot find Zone 17S in the Data Frame Properties Coordinate System choices. Any suggestions? I tried ArcGIS Help, but it does not help. We do not have any of the specialized extensions, so I need a simple fix. Thx