How can I mirror part of another server?
Scripts are available to do this, but at this time they are not very
friendly to the server you are attempting to mirror; their behavior
resembles that of the more poorly written WWW robots.
If you are trying to improve access times to a distant server, you
will likely find the "proxy" capabilities of
CERN's WWW server to be a more
effective and general solution to your problem.
World Wide Web FAQ