I'm new to the VSTO and trying to add a custom toolbar to all new email
messages.  I've successfully run the sample code at

http://msdn2.microsoft.com/en-us/library/ms268864(VS.80).aspx

that adds custom toolbars to Outlook.Explorer.  From my limited research,
I've tried modifying the code to add the toolbar to Outlook.Inspector
instead.  I modified the line

Office.CommandBars cmdBars =
           this.ActiveExplorer().CommandBars;

to read

Office.CommandBars cmdBars =
           this.ActiveInspector().CommandBars;

The add-in fails on this line with the error message: "Object reference not
set to an instance of an object."

Any suggestions or samples of adding a custom toolbar to an email and not
the main Outlook (2003) window?