square bracketed noteheads & other elements

[Tammo]

Hello,
I've been using Lilypond for half a year already and I have managed myself
so far. But now I'm stuck and publisher is already knocking on my door..
I need to add square brackets to noteheads, articulations,
accidentals and noteheads with accidentals for editorial remarks.
I found a snippet \bracketify but it only works for notes and
only for all notes in a chord.
http://lsr.dsi.unimi.it/LSR/Item?id=564

Firstly is there a way to change \parenthesize so it always shows
square brackets instead of parenthesis (I don't need to use them at all)?
This way i could "bracketify" noteheads and articulations.
But then there are still accidentals alone and noteheads with
accidentals what need to be bracketed.
Like this:
[#]c  and  [#c]

I've come from musical world and don't know Scheme or any
other programming language to be comfortable with it.
So I'm quite noob here and hope you can help me.
I have already tried adding brackets with vector editing programs
so it shows how desperate I am.

With regards,
Tammo