No "link" to specific letter unless content present?

I love this module! It is so all inclusive for a directory type use that is easily broken up by content type!

Wondering if anyone has any ideas of how it might be customized so that if there isn't any content under a single letter, then it remains as read-only text UNTIL a node of content under that specific node type is placed there.

(EG. if there isn't any content starting with the letter "B" then it remains only text and not linkable UNTIL a piece of content is placed under that does start with "B"?)

Lisa