up2date and channels

[Mark]

Hi,

I use up2date and have configured a bunch of channels in /etc/rhn/sources
This works as long as I don't have conflicting packages in the different
channels.
But if I for example have both a mysql and and an fc1 channel with mysql
rpms, I want to be able to pick which one I want to up2date against. I tried
the channel parameter, but apparently that one is only used in connection
with a special up2date feature (I think getting the list of all available
packages or something), not with a regular up2date run.

Is there a way to tell up2date to run up2date for a certain package against
one particular channel?

Thanks,

MARK