I can’t promise anything but I’ll try create an example project for you - I’ll let you know how I get on.
Edit: So you’ve stumped me. I tried it and only got so far; Without the Portal stuff from UE3, It’s quite hard to get what you’re setting out to achieve. I managed to fake a second character in level #2 with a scene capture on his head to “fake” it but up close you can see this isn’t the ideal solution.
Hope this information helps in some way.