Thanks Ralf! I got it to work by making sure the resolution of Skyrim is 1920×1080. And i set my other monitor to extend desktop instead of clone with my rift as primary monitor. makes it a little tricky to start a game but hey it works.
Skyrim looks really great with the rift so kudos to vorpx for making it work.
One problem I have is the foliage in the game seems to be flashing a little bit (like a neon lightbulb, but only a small value change) which gets nauseating after a while. It could be my quality settings are too high though. have to experiment.