click track lead-in invisible bar

[Jim Tisdall]

I'm generating a click track.  I need it to start a measure
(or two) before the music in a staffgroup.  I want the extra
beginning measure to be hidden, so it doesn't show up in the
typeset score, but just sounds in the midi output.  I already
have the clicktrack hidden.  I just need it to start a measure
early, without displaying an empty measure in the score.
Thanks for considering my problem, any pointers or suggestions
will be most appreciated. -- Jim Tisdall