Running headers dictionary-style?

[Eric Van Tassel 101233.342@xxxxxxxx]

Can anyone help me?

I want to create running headers for an index; and I want the header on each
page to be of the type (I don't know the terminology for this) that includes the
first 5 characters of the FIRST AND LAST headword of the index.

This may be easier to explain than to describe. The index is of Schubert's
songs, with discography. Each entry begins with the song title and certain other
data, and continues with a list of recordings broken out with s and
s. Thus page 1 currently begins
  ≪NB≫≪MD+BO≫Abendbilder≪MD-BO≫ D.650 ≪MD+IT≫Silbert≪MD-IT≫
  1969--recording no.1
  1982--recording no.2
and ends
  ≪NB≫≪MD+BO≫Am Grabe Anselmos≪MD-BO≫ D.504 ≪MD+IT≫Claudius≪MD-IT≫
  1966--recording no.1
  1970--recording no.2
  1990--recording no.3

These are "soft" page turns (effected by the ≪NB≫), *not* using ≪PG≫ in the
file, because as I revise the discography periodically the page turns don't stay
in the same place. What I want the headers to do, in this example, is pick up
the NON-indented part of each entry; so that for the example just given the
running header would read

  Schubert lieder≪LD ≫[date]≪LD ≫p. ≪PN≫ of ≪FP≫≪LD ≫Abend - Am Gr

I'm looking for a macro that will pick up the characters "Abend" and "Am Gr".
Anyone have any suggestions?

Thanks.

Eric Van Tassel