There is a simple way of doing what you want. Go to:
http://www.kainjow.com/ and download Bootchamp.
Blurb from website: BootChamp is a small utility that when launched, will boot your computer into your Windows partition. It requires authentication in order to properly set your Windows partition as the startup disk.
How is this different than selecting your Windows volume from within Startup Disk in System Preferences? Well, using Startup Disk actually changes your startup disk permanently so that each time you restart, it boots into whatever you have selected. Essentially what my program is doing is what happens when you hold down Option at startup and select Windows. However, the app only requires a click to launch and your admin password, and then it restarts your computer into Windows without further input from you. It will not actually change your startup disk.