You can import XP icons to 2000 if someone will send you either the icons or the .dll files they're stored in, but they won't have the alpha blending in 2000.
There is a program called XP Icons that will replace all the standard icons in windows 2000, me, 98, and maybe even 95 with the xp icons. Its shareware, but, as I recall, when I used windows 2000 I was able to forceably remove the program whilst retaining the icons. I think I might have just saved all the icons it replaced and then uninstalled it, either way, its possible to get them without spending $20 for the program. (and of course I don't mean cracking the program or using an illegal serial number.)
All windows since 95 just needs you to edit the registry's shellicons thread, and some few other threads. 3rd party proggies are there to make the job easier, not there to give extra features, unless we are talking about animated graphics replacing native icons. But if you are using the newer xp/alpha-masked icons on pre-XP Windows, please graphically edit them first. Or else you will see icons with very ugly edges.
+| he who will kill the god if given the slightest chance |+