Dear all,

I have some mrsid files I need to work with on Civil 3D (2016).
Each mrsid file contains it's georeference and for each image/map I have 2 files.
- .sid which is the image/map
- .sdw which contains the geolocalization for the image

I was abble to add the mrsid image file onto Civil 3D and already found how to add a coordinate grid using the layer view.
(defined coordinate system / add a Reference System on layout view under Layout Tools Menu)

The maps have been made using Camacupa Datum and are on 1:100.000 scale.

My actual problem:
My problem is that I do not need the full map itself. I just need to work with a specific area of the map and want to add the coordinates on this area.

I cannot find a way to "cut" or "select" the desired area in order to work with, and add the reference system on this smaller area of the map.
I have tried to add new viewports and select only the desired area but on every viewport I create, the full map is shown.

Is there anyway I can select just an area of the map to work with under Reference System in order to add the coordinates grid?

Thank you very much

Paulo