Accessing Global Address List - Custom fields

I'm trying to access the Global Address List from a MS Access database I'm developing through VBA Code...

I've got to the stage now where I can view the Name, Manager, ID etc... of each entry within the Address List, however, when I look at the actual address entry display form from within Outlook, there is much more information I would like to access apart from Name, Manager, ID etc...  such as Employee Number, Position, Location etc...

The Global Address List is generated through Microsoft Exchange - I work in a large organisation and am not directly associated with the IT section, but I'm assuming the extra fields I'm chasing are custom fields that have been added by the organisation.. and hence, are not easily accessed via   AddressEntry.[property]   through VBA code...     I was thinking that the code objAddressEntry.Details([HWnd])  may be a way in to this additional area, but I'm running a bit blind here and really have no idea how to get the info I want...

Any suggestions would be appreciated..

Thanks in Advance