Found this in an online manual which I acquired: -
From Navigation mode: -
To show the menu: press the COMAND controller.
Select Destination in the navigation system menu bar by turning the COMAND controller and pressing it to confirm.
Select "Using Geo-Coordinates" and press to confirm.
An entry menu appears.
You can now enter the latitude and longitude coordinates with the COMAND controller or the number keypad.
To change a value: turn the COMAND controller.
To move the mark within the line: Slide the COMAND controller.
To move the mark between the lines: Slide the COMAND controller.
To confirm the value: Press the COMAND controller.
If the selected position is outside the digital map, COMAND uses the nearest digitized road for route calculation. You will see the The coordinates are outside the map area message. If the selected position
is located over a body of water, you will see the message: The destination is in a body of water. Please select another destination.
Hope it helps, though not sure which version it's for. It seems to work on my W212 though.