[O] modify the org-format-latex-header include matlab-prettifier and its complicated options

[Uwe Brauer]

Hi I would like to have the following header when exporting from org to
latex.

\usepackage[numbered,framed]{matlab-prettifier}
\let\ph\mlplaceholder
\lstset{
style              = Matlab-editor,
basicstyle         = \mlttfamily,
escapechar         = ",
mlshowsectionrules = true,
mathescape=true,
morecomment=[s]{\%\{}{\%\}},
}

(This is and enhancement of the listing package)

So I boldly set


(defcustom org-format-latex-header "\\documentclass{article}
\\usepackage[usenames]{color}
\[PACKAGES]
\[DEFAULT-PACKAGES]
\\pagestyle{empty}             % do not remove
% The settings below are copied from fullpage.sty
\\setlength{\\textwidth}{\\paperwidth}
\\addtolength{\\textwidth}{-3cm}
\\setlength{\\oddsidemargin}{1.5cm}
\\addtolength{\\oddsidemargin}{-2.54cm}
\\setlength{\\evensidemargin}{\\oddsidemargin}
\\setlength{\\textheight}{\\paperheight}
\\addtolength{\\textheight}{-\\headheight}
\\addtolength{\\textheight}{-\\headsep}
\\addtolength{\\textheight}{-\\footskip}
\\addtolength{\\textheight}{-3cm}
\\setlength{\\topmargin}{1.5cm}
\\usepackage[numbered,framed]{matlab-prettifier}
\\let\\ph\\mlplaceholder
\\lstset{
style              = Matlab-editor,
basicstyle         = \mlttfamily,
escapechar         = \",
mlshowsectionrules = true,
mathescape=true,
morecomment=[s]{\\%\\{}{\\%\\}},
}
\\addtolength{\\topmargin}{-2.54cm}"
  "The document header used for processing LaTeX fragments.
It is imperative that this header make sure that no page number
appears on the page.  The package defined in the variables
`org-latex-default-packages-alist' and `org-latex-packages-alist'
will either replace the placeholder \"[PACKAGES]\" in this
header, or they will be appended."
  :group 'org-latex
  :type 'string)

So at first that looked ok, describe-value gave me the correct new
value, but when exporting from org to latex the new modified did not
have that header, than I thougt of using

(customize-option (quote org-latex-packages-alist))

But that option seemed not flexible enough.

So what can I do?