Controlling Outlook and other MS Office programs is known as "Automation". To get information on accessing the Outlook addressbook you may search for "outlook automation addressbook". See also the MSDN [
^]. There are only few examples for C++. Most are for VB and C#.
When using Outlook Express, you may access the Windows addressbook with the
IAddrBook
interface [
^] that is used by the Express version.