Using any camera as maincamera.

I have a "server-cube" with 6 cameras attached, one pointing in each possible direction ; N,S,E,W,U,D., named "cameraN", "cameraS" and so on.

When running, this application will act as a server, and will only use the one pointing down, while the other cameras should be used by other "slave-apps" connecting to it.

The application that connects to the server will have only one function; to display the image from one single camera, which one will be selected via GUI - and that is all.

I have the networking down and I understand how to get the GUI working. What I need help with is; How do I get my "slave-app" to use one of the cameras on the "server-cube" as its maincam?

I know the answer is probably easy but I am new to Unity and scripting so right now I am experiencing information overload. It is a case of not seeing the forest for all the trees.

It would be great if any of you wizards could help me in the right direction.