You'd have to write your own code to do that, getting the current user in an
Open event and preventing Write or Save and disallowing PropertyChange and
CustomPropertyChange as needed. There's no built-in way to do that.
Globally you could do that based on where the form is stored (which folder)
by setting the folder ACL's, but that's not a granular method that could
allow field by field locking.

Signature
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Absolute Beginner's Guide to Microsoft Office Outlook 2003
Reminder Manager, Extended Reminders, Attachment Options
http://www.slovaktech.com/products.htm
>I am using Outlook 2003 with exchange server, and am in the process of
> creating a public database, with custom designed forms. Does Outlook allow
[quoted text clipped - 3 lines]
> cannot edit this field?
> Any help gratefully received