funktionsbezeichnungen

[Stefan Thomas]

Dear Lilypond-users,
 does someone know if it possible to create "Funktionsbezeichnungen",
like "T" "D",etc. ?
I tried the example below, but the problem is, the "7" must on the
same level like the "5". Also the "T" and "D" should be a little
lower. What can I do?

global = {\time 3/4 \key aes \major}

upper = {\skip 2.} 
under = \relative c { 
\global \clef bass 
s2._\markup {T} s2._\markup {D \super \small 7 \sub 5 }
 
}


\score { 
\new PianoStaff 
<< \new Staff = "upper" \upper
\new Staff = "under" \under >>
}