\version "2.11.46"

\header { title = "Test title " }

%%% Nicolas' solution needs the parser:
% #(define-public (add-toc-item parser markup-symbol text)
%   (collect-music-for-book parser
%    (add-toc-item! markup-symbol text)))
%%% How do I get the parser from inside a markup command?

#(define-markup-command (piece-title layout props title) (markup?)
  (add-toc-item! 'tocItemMarkup title)
  (interpret-markup layout props (markup #:bold title))
)


\paper {
  % Doesn't work...
  scoreTitleMarkup = \markup \piece-title \fromproperty #'header:piece
}


\markuplines \table-of-contents
\pageBreak
    
% Doesn't work...
\markup\piece-title "Something"
% Works:
#(add-toc-item! 'tocItemMarkup "Irgendwas")
  
\score { \relative c'' {c4 d c d}
  \header { piece = "Nr. 1 - Text" }
}

\score { \relative c'' {c4 d c d}
  \header { piece = "Nr. 2 - Was anderes" }
}


%%%%%%%%%
% Problem with adding a label inside a markup:
\markup { Some interesting point \label #'refA. }
\pageBreak
\markup { As mentioned on page \page-ref #'refB "0" "?", there is something interesting. }