You can find at http://jpq.pagesperso-orange.fr/nwc2/nwc2ly.html a converter NWC to Lilypond in Java
My reading of the French says that this utility improves on the one I've written since it deals with complete songs/scores (I think). That's not true. My noteworthy to lilypond converter will convert complete scores and allow users to take advantage of the typographical excellence of lilypond for large scores. I commend it to all who have recently been discussing workarounds for noteworthy layout.