If you search "coordinates" in the map 3d forum >>here<, there is some code available. If you still have questions, I suggest you post there.
Here is some vb to get all coordinate systems - there were more than 5,000 systems available when this was done for Map 3D 2011.
Private Sub GetCoordinateSystems(ByRef systemcounter As Integer)
Dim msg As String = "GetCoordinateSystems" & vbCrLf
Dim csyssysfac As New MgCoordinateSystemFactory()
Dim csyssyscat As MgCoordinateSystemCatalog = csyssysfac.GetCatalog()
Dim csyssysdic As MgCoordinateSystemDictionary = csyssyscat.GetCoordinateSystemDictionary()
Dim csysenum As MgCoordinateSystemEnum = csyssysdic.GetEnum()
Dim csyscount As Integer = csyssysdic.GetSize()
Dim csysnames As MgStringCollection = csysenum.NextName(csyscount)
Dim csysname As String = Nothing
Dim csys As MgCoordinateSystem = Nothing
Dim csystype As Integer = 0
systemcounter = 0
For i As Integer = 0 To csyscount - 1
csysname = csysnames.GetItem(i)
csys = csyssysdic.GetCoordinateSystem(csysname)
csystype = csys.GetType()
systemcounter += 1
Next
msg = msg & "systems counted " & systemcounter
'MsgBox(msg)
End Sub 'getcoordinatesystems