HiddenMessages is a collection in CDO 1.21 of the Folder object, it's what's
shown in OutlookSpy as Associated Messages and contains all the hidden items
in the folder.

As Michael said, the error is coming from Message.Add, which doesn't exist.
Once you get your Messages collection from HiddenMessages you would use
Messages.Add.

There's some information about the properties for archiving at
www.cdolive.com/cdo10.htm. Also, take a look at
http://www.cdolive.com/archiveviewer.htm, which uses those properties to
view autoarchive settings. It does a lot of what you want to do.

--
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