The Microsoft LifeCams are directly attached to computers. They are not IP cameras, and can only be seen directly from the computer they are plugged into.
Using WebCam Monitor, you can stream the video from your camera to other computers. In that case, yes, you would use the mms:// stream. The actual URL to use will be displayed in the program's Event Log when you start streaming.
If you would like to view your camera over the Internet, you may have to use Port Forwarding. The technique to do this is explained in our article, Configure Your Camera and Router for Internet Streaming.