Actually, I started doing this, but it doesn't save.
IE, when using my standard VGA, I use 1024x768. When I would change it to 640x480, it would go back to 85hz. It was a configuration nightmare. The only way to get it to work was to switch it when the EYGO monitor was connected (and scrolling)... ie, not good
Then I went and forced all refreshes to 60 (telling windows that my monitor only supports this) and everything started working well switching back and forth.