Commands to get data from Active Directory

Hi,
I am looking for a tool or a command to retrieve information from AD. We have 2003 systems and we have users who move between
sites because of which there mailboxes lying
in different locations. We are trying to
create Distribution Lists accroding to site and for that I need to retrieve information from the Exchange Server with the Name and the server name on which the users mailbox is present.

Can anyone help me with this.