Custom symbols for noteheads

Is there a feature (current or planned) to use customs symbols for noteheads? By "custom" I mean symbols that are not included in the built-in font.

In the attachment, there is an example of what I would love to achieve.
( More about this notation system here: http://musicnotation.org/musicnotations/2linesmajorthird.html#braunstein )

Cheers,
Jan