How to find specific text WITHIN iTunes lyrics?

Question

I've been trying to figure out how to search within existing iTunes song lyrics for specific words or phrases, for the purpose of making specific playlists of all songs that contain the specified text.
As an example, I'd like to find all the songs (out of a couple thousand or so) that contain the word "Instrumental" and place them in a list.  Perhaps from there, I'd change all of those songs' Comments to show "[Instrumental]" or some such to make it easier to use some of iTunes built-in tools, or your own excellent ones.
Or maybe I could look for songs that have the word "Notice" in them, so I can examine their lyrics to spot those which only had partial lyrics auto-loaded to them, so I could do a more thorough manual search.
Thanks,
  Ed

Answer 1

I think I'm on the good way with this:
    app.findTextPreferences = NothingEnum.nothing;
    app.changeTextPreferences = NothingEnum.nothing;
    app.findTextPreferences.findWhat = "CAR67765756";
    app.changeTextPreferences.changeTo = "bhbdbds"
    found = app.activeDocument.findText (true);
    if(found.length>0)
        for (j = 0; j < found.length; j++)
            found[j].select();
            alert("true");
            app.documents.item(0).changeText();   
    else
        alert("false");
    app.findGrepPreferences = app.changeGrepPreferences = null;
    app.changeGrepPreferences = app.changeGrepPreferences = null;