I finally figured out how to use the Document.Selection of Nikhil's HTML Component. I was looking for Document.InsertHtml which eluded me until today. This is really great - one of those hidden gems that wasn't so hidden once you saw it.
So anyway, I'm making headway on this project, little by little (work and all). Here's what I got from a simple dialog and syntax highlighting:
Hopefully before too long we'll have a maiden post.