Encapsulating tweak and markup in a variable

[Menu Jacques]

Hello folks,

In order to produce home-make fingerings, I use the code below, a solution 
supplied by users of this list:

%%%%%%%%%%%%%%

\version "2.19.15"

Introduction =  \relative g, {
  \markLengthOn

  \clef "bass" \key bes \major \time 2/4 | % 1
  \tempo "Moderato" 4 = 108

  g2 \mf
  -\tweak TextScript.self-alignment-X #CENTER
  ^\markup{\large\bold\with-color #magenta "1E"}
  | % 2
  g2
  \bar "||"
}

{\Introduction}

%%%%%%%%%%%%%%



My attempt to define a variable UN_E to obtain the same effect:

%%%%%%%%%%%%%%

UN_E = {
  \tweak TextScript.self-alignment-X #CENTER
  \markup\large\bold\with-color #magenta "1E"
}

{g2 \mf ^\markup{\UN_E}

%%%%%%%%%%%%%%


leads to error messages:

Users/menu/Documents/LaTeX/PartitionsLilypond/DoigteAndTweakAsVariable.ly:26:3: 
Erreur : type d'argument erroné pour 3.
 Attendait symbol list or music, (markup #:large (#:bold (#:with-color (list 
1.0 0.0 1.0) "1E"))) trouvé
  
  \markup\large\bold\with-color #magenta "1E"
/Users/menu/Documents/LaTeX/PartitionsLilypond/DoigteAndTweakAsVariable.ly:29:18:
 Erreur : syntax error, unexpected MUSIC_IDENTIFIER
{g2 \mf ^\markup{
                 \UN_E}
/Users/menu/Documents/LaTeX/PartitionsLilypond/DoigteAndTweakAsVariable.ly:29:24:
 Erreur : Fichier principal non fini
{g2 \mf ^\markup{\UN_E}


Thanks for your help to sort this out!

JM