CDO knows nothing about search folders at an object model level and is not
supported at all for use in managed code besides that.

The Outlook 2003 object model has no specific search folder properties,
methods or events. A search folder is created using the Search object and
saved, that's about it. You can delete an existing search folder and
re-create it using the same filter and search conditions, that's about it.

Outlook 2007 isn't much better in that respect, it has a
Store.GetSearchFolders() method but no search folder specific objects other
than that.

If you use the Redemption 3rd party library (www.dismastr.com/redemption)
you can use the RDOSearchFolder object and its Start() and Stop() methods
and its IsRunning and IsRebuild Boolean properties to determine the search
folder state and control that state.