Local yum repo

[Gene C.]

I have a number of systems I want to be able to update and would prefer to 
download updates across the Internet only once.  Therefore, I would like to 
create a local repo.  OK, I know how to create the local repo and have done 
that.  There problem is that I want to keep the regular repo mirror lists 
also but have yum pull the updated packages from one of the mirror lists 
sites ONLY IF that package is not available on the local site.

Just adding /etc/yum.repos.d/fedora-local-updates.repo does not do it since 
the updates are still pulled first from the release-updates mirror sites.

My /etc/yum.repos.d/fedora-local-updates.repo is:

[local-updates-released]
name=Fedora Core $releasever - $basearch - Local Released Updates
#baseurl=http://download.fedora.redhat.com/pub/fedora/linux/core/updates/$releasever/$basearch/
baseurl=http://amber.home/redhat/fc4/Updates/$basearch/
#mirrorlist=http://fedora.redhat.com/download/mirrors/updates-released-fc$releasever.us.east
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora

Suggestions?
-- 
Gene