Notehead scheme

I would like to request a numbered note head scheme. It seems like it would be quite easy to replace the solfege (moveable) scheme with numbers, but I do not know how to make plugin's. For instance Do would be 1, Re would be 2, Me=3, Fa=4, So=5,La=6, Ti=7. This would be very helpful in teaching my 5 year old the Hayden Concertina (a system which uses the same fingering for every scale).