Exchange – Dist. Groups in Pub. Folders

I’m running Exchange 5.5 and I am running into a problem with distribution groups. I’ve been researching whether or not you can put distribution lists in a public folder while still being able to see them in the global address book. Is there a wayto do this, or to set up a public address book so that users can use the “To” button when composing an email and select the group they want? I’m trying to avoid setting up a regular distribution list because I want to keep internal and external emails and lists seperate.
Thanks in advance

-jtrudel