I don't think you want to do that. Are you planning on deploying a Rails app? Or do you want to develop on a windows machine and deploy it later?
All you really have to do to test your app in development is boot webbrick on your Windows box.
change directory to the application root, and
ruby script\server -b locathost -p 3000
then enter this url in your browser
If you really want to deploy a rails app and apache and mongrel, on a Windows server....
God's speed John Glen............
Joe got a job, on the day shift, at the Utility Muffin Research Kitchen, arrogantly twisting the sterile canvas snout of a fully charged icing anointment utensil.