Public folder distribution lists

We have a public folder of contacts on the server, and have set up a dl so we can do a mailshot to them. However, when the message goes out it shows all the email addresses of the recipients in the to column. We don't want everyone to see everyoneelse on the list.

We can set up a container in the Exchange schema and make a dl in there which will hide the addresses, but this any changes to this would have to be done by an administrator. By doing the list in public folders, we can put a user in charge of administering the contacts.

Is there any way of hiding the addresses of a public folder dl, or can anyone think of a way of achieving this without using exchange admin?