In order to use more than one non modifier keys in a shortcut your keyboard needs to support n-Key rollover. For a technical description of what that is read this article.
Around the middle there is a text field and instructions to test your keyboard. My keyboard dropped half the alphabet, so I can't tell you what to do next, sorry :-(
Edit : I did some research and the only way to achieve something close to what you are looking (that I could find) is autokey. Although not a "pure" shortcut solution, I think you can script it to perform the action you desire.