What I'm about to say is completely unqualified information, so please don't rely on it...

From what I've heard the process is very long and very expensive in CH. Best option is to do outside the country and then have your licence converted. But there's a catch - you have to have been away for more than 12 months to get away with it. They obviously want to stop people going away for a holiday and doing it. I believe the same kind of rules apply to getting a driver's licence outside of CH.