[Yum] Overriding specific packages

[Fredrik Tolf]

Hi list!

Please forgive me if I'm just blind, but I have looked and looked
without finding anything on the following subject, even though I think
it ought to be a rather common thing to do.

What I'd like to do with Yum is to "override" specific packages with
local versions. For example, I've patched screen with some Kerberos
support, and would like to use it instead of the screen in my distro's
(Fedora) repo.

If I'm not mistaken, just packaging it as an RPM and installing it
wouldn't cut it, since that would make Yum overwrite it again with
Fedora's version the next time Fedora decides to throw an upgrade at me,
right?

So, does anyone have any tip on how to accomplish this? It is the second
most important reason why I'm currently using Gentoo on most of my
systems.

Thanks for reading!

Fredrik Tolf