You can download the latest MFC MAPI utility to view GAL entries, which uses the Messaging API to provide access to MAPI stores through a graphical user interface.
Try the following steps:
1) Open MFC MAPI utility. Select Session menu and select “Logon and Display Store table” ( I chosen for this session). It will ask you prompt the profile.
2) Select the profile. Once you select it, it will open the stores associated with it.
3) Select Address Book Menu and select "Open Default Directory” option
4) It will list out the GAL entries
5) If you select a GAL entry in the top pane, it will display its associated properties, tag, type, value etc in its below pane.