Sorry for not answering your exact question; I simply think the idea to link the size of application to the size of the screen is wrong. When a user purchases a monitor which is twice as big as the previous one, she or he does not want to have application windows scaled by two. Instead, more typically, she or he hopes to see four times more information at the same time. By your request you break this hope.
Also, it's much better to write resolution-tolerant applications. You will find some ideas in my past answers:
GUI Apperance - C#.Net[
^],
Zom Out malfunctions when Screen resolution changes[
^].
—SA