It's completely unsupported, but if you set up for an Outlook 2003 VSTO 2005
SE addin and use the Outlook 2003 PIA and then change the Office reference
to an Office 2007 reference you can do what you want. Of course you would
only be able to support the Outlook 2003 object model using early binding
and could only use late binding for methods and properties added in Outlook
2007. Outlook 2007 events you couldn't handle at all.

--
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


"Michael" wrote in message
...
I have written an Outlook 2003 shared add-in, and it seems to run pretty
well in Outlook 2007. I am planning on migrating it to VTSO 2005 SE. I'd
like my add-in to run equally well in Outlook 2003 and Outlook 2007.
However, if it's running in Outlook 2007 I'd like to be able to take
advantage of some of the new features, like using RibbonX instead of a
toolbar that's placed on the Add-ins tab on an Inspector window.

Is this possible?

Michael