Dudes look this up. It caught my attention quite sometime ago. Not a bad mod for your concept. The battlefield spans a couple of maps and is considered campaign play in multiplayer.

"Also come with a revolutionary feature called War Server, which will transform a single server in a full war, with many different battles and a final objective to complete."

All you need to do is learn how to set it up. Shouldn't be too hard.

Happy Hunting.

The Link: http://www.mods.hajas.org/