scripting and forcing windows update

Hi,

This is dead easy on other operating systems, but I can't find the
simple way to do it on Windows.

All I want to do is run a script that will force Windows to immediately
download and install all available critical updates. I don't want to
have to run a sus server, a wsus server, or any local cache of the
updates.

I just want to have one command line to run like I can do on Red Hat,
Mandriva, SuSE, Fedora, CentOS, Debian, Mac OS X, etc. Something like:

winupdate /update /force /critical

Any ideas?

Thanks,