You can't redirect a 'top URL' to a 'deep URL' in Apache itself, so you can't do, e.g.
Code:
Redirect / http://mailman.example.com/mailman/listinfo/
in the mailman.example.com vhost config
You can redirect a different vhost like
http://list.example.com or
http://mailman.example.com to
http://lists.example.com/mailman/listinfo/ though.
Using a
redirecting .html page in the DocumentRoot should work.