multimeasure rest with no number of measures?

[Chip]

I would like to use a multi-measure rest, the long horizontal solid bar 
style, to indicate a rest period of any number of measures. I am trying 
to print lead sheets for some raggae music and the singer often changes 
things from one gig to the next. The horn players just listen for 
certain cues to indicate when they should play. I want a multi-measure 
rest with no number on it. Should be able to make on with any number 
then make the number invisible?
Thanks,
Chip