I'm using TH2Go at 3840x1024.
Path in cmd will start with E: <-Note the colon. For example, to change to E drive windows folder type E: at the command prompt first and press enter. Then type CD\WINDOWS.
Try copying the camera file to a temporary folder on your C: drive along with the binXML files etc, doing the mod there, then copying the modded file back to your E: drive
What camera do you use? I have only modified Williams and Redbull, but I can send you my files if you like. I only ever race in cockpit view, so have only modified that camera. I have also reduced the head shaking which gets pretty out of hand in close FOV.
Edit: Chad's files *may* be for a single widescreen, and so may well look stretched in triple screen. I'm using a FOV value of 38.5 for Redbull, and a very very slightly higher viewpoint so I can see both mirrors fully. Not sure what values Chad uses.