How can I frame a rule to achieve this?

By adapting the examples in the File::Find::Rule documentation to your needs. Did you actually read the documentation? You set up a @exclude_dirs with qw(OLD). And? what for? you don't use it anywhere.

A recipe to exclude a directory is in the documentation under the sub-heading "Further examples" following "ignore CVS directories".

Your code looks like whipped up to provide at least something to fend off the "no code" argument; but you seem to be trying to use The Monastery as a coding service, which it is not.