I think you hit it with your last question. The ability to have a separate profile for two different monitors is built into Macs. With Windows it’s not so easy. If you’re on Win XP, you’ll need the Color Control Applet to define which screen gets which profile. And even then, it is doubtful that you would get separate profiles for each display without installing a separate graphics card. Vista does not seem to have the same problems using two displays.
[url]http://one.imports.literateforums.com/t/2-monitor-profiles-in-windows-xp/593/1]
If you’re stuck with what you’ve got, you could at least “mirror” your displays so you can go through the software procedure for calibrating your external LCD. Then, you will have your external LCD properly calibrated and your laptop will have to suffer along with the same profile as the external screen.