Outlook 2k/XP/2003Contacts Maintenance

I am running a linux, mail/webserver but all our clients here are running windows XP/2000. They use outlook express or outlook, at the moment they have to update and maintain their own contacts list, is there any way that i can have one comapny contact list, that I myself updates when new employees come and go that will automatically update the clients address books.
Any help would be greatly appreciated