Pin package versions in RHN?

Is there a way in RHN/Satellite to pin versions of packages to ensure that they don't get upgraded past a certain version? I have some custom applications that require certain packages to be locked at particular versions. I'm looking for the best practice way of doing system updates without having to do lots of tweaking.

Ideally, I'd like to be able to go into RHN/Satellite and select certain package versions for these particular servers and then be able to let regular system updates do their thing without having to worry about new versions clobbering the required old ones.

The way I do this is to create clone channels, and then only clone the errata I want from the upstream channel into the clone. It take a bit of effort to make sur you don't clone an errata that has a dependency on an errata you don't want, but it effectively pins package versions at whatever level you stop cloning errata.

This might be useful from the man page for yum.conf:

exclude List of packages to exclude from updates or installs. This should be a space separated list. Shell globs using wild-cards (eg. * and ?) are allowed.

So if you set