E2k3 dublicating e-mail messages to another user’s mailbox

Hi,
I’ve got e2k3 running w2k3. There are a lot of group-based distribution lists in the address book. One of the executives wants imlicitly and automatically receive messages addressed to some of these distribution lists.
How should I configure E2k3 to implement this scenario without merely adding executive’s account into each of these distribution list?
Thanks.