Programatically setting the default form for a folder

Hi all,

I have a custom MS Outlook Contacts form, which I have published into
Outlook.  I also create a new Contacts Folder under the default contacts
folder object.
What I would now like to do is to set the custom form as the default form
for that folder.  It's easy enough in MS Outlook, you just right-click on
the folder, go to properties, and change the 'When posting to this folder,
use:' field.  Can that be duplicated using OLE?  It seems that the message
class for a folder is read only.

Thanks in advance,

Artur Czernecki.