Silverlight Viewer - Disable some edit tools?

Folks,

We'd really like to be able to have the control to disable one or more of the edit tools. I'm in the process of writing a very simple to use Add New Feature workflow which is invoked from a Button on the toolbar. This workflow goes off and queries tables etc for firenames, event ids etc, that are not in the spatial domain as yet until the user creates the point, line or poly shape - hence I can't use the Add new feature tool in the Edit Tools region, and hence why I'd like to disable this tool in particular from the edit region... I'm effectively giving the user 2 ways to add features, and only one is the correct way... We will use the Normal edit tools to 'modify' features once they are created...

hope all that makes sense ; )

cheers

Gareth