Add features to RTF Cntrl

Doe's anybody know where I can get the source code for RichText Edit control.
I want to be able to add new capabilitys. Specificaly I neet a control to make a a custom editor for working with Guitar music, I need to add ability to work with chords ( not graphical - just the symbols) and be able to transpose them. I was thinking to add special formating code to the text stream to add the chord symbols and display the chord above the line (lyrics).
Email: [email protected]

David G. Schwenk
[email protected]