I don't think you can copy auto-updates for re-installation at a later date. If you want to keep an archive of windows patches and updates to install as and when you want, you have to go to Microsoft's Download Site, choose updates from the list which apply to your OS and other Microsoft Software, then download each one and save it somewhere -- then install each one yourself.
http://www.microsoft.com/downloads/P...n&categoryid=7
Auto-updates do away with all that hassle by automatically detecting what you need and installing it -- the downside is the updates aren't saved for repeat installations.