Outlook 2003 – nick name

Dear Tech Support,

How to change the display nick name at the To: CC: or BCC: field. My current display nick name is, for example, David Lim David Lim is the user name and david.lim is the email address without the email domain name.

Note: I deleted the .NK2 file and create a new one. Can not find any clue at the user’s property of the AD User.

The environment is
Exchange Server 2003 (SP1) running on Windows Server 2003 (SP1)

Outlook 2003 (SP2) running on Windows XP (SP2)

Thank you very much.

Regards,
Yo K.K.