repoquery

http://yum.baseurl.org/wiki/RepoQuery

#List the repo
$ repoquery -qa --repofrompath=,your_repo_server_url --queryformat='%{NAME}.%{ARCH} %{EPOCH}:%{VERSION}-%{RELEASE}'

#Get location of rpm
$ repoquery -qa --location --repofrompath=,your_repo_server_url name_of_rpm

[Note]
somehow, the cache will be in the system, if you dont want that, remove it before you do repoquery...

/var/tmp/yum-XXXX