Right Click Mouselook and Two Button Running

Okay, so I've been searching for this, and as of yet I haven't found what I am looking for. What I need to do here is have mouselooking disabled by default in gameplay, so the cursor is always on the screen. The user would then press and hold the right mouse button to mouselook. I'm figuring the changes would need to go into the default.keybind.cs.

Also, is there a way to make it so the user can mouselook and run forward when BOTH mouse buttons are pressed at once, without making the left button send the player forward when pressed by itself? I still need the left mouse button for selecting interface elements on the screen.

Any help would this would be greatly appreciated.