Hi. Yes, you should be able to run Bridge Command on multiple monitors on the same PC.
To do this, you have multiple versions of Bridge Command running at the same time, with one controlling the scenario, and all the others just showing the 3d display or radar.
So yes, I think you should be able to do what you describe. Bridge Command doesn't give you an ECDIS display, but does provide NMEA data that can be used by an ECDIS.
So I think you would have:
Left screen: ECDIS program, recieving NMEA data from Bridge Command (this is set up by default, and Bridge Command will send NMEA data over UDP on port 10110 by default. You should be able to receive this in an ECDIS program)
Right screen: Radar display. When you start Bridge Command, you should see a little pop up window asking which screen to use. Drag this over to the right screen, and then choose 'Use as a secondary display'. You can then choose the full screen radar display.
Main screen: The main view and controls. This time drag the little pop up window to the main screen (if it isn't already there), and in the hostname box, type localhost (this will ensure that it sends data to the secondary program). Make sure you've started the secondary one before this.
Let me know if you have any queries or problems!