printing "a 2" at the beginning of staves automatically

[Werner LEMBERG]

Let's assume that I have 40 bars of flute 1 and 2 in a single staff of
a full score.  At the very beginning of these bars I write "a 2", and
I want this remark repeated at the beginning of every staff where this
is still true.  [Obviously I'm not using `\partCombine` :-)]

Has anyone already set up such a thing?  I looked into the LSR but
could find something related.  It seems to me that a text spanner
could do it, but it shouldn't interact with any other (text) spanners.


    Werner