The easiest way is to create the piece with all the desired staves, then enter the music on the staves desired. Then, when everything is entered, highlight the staves you DO NOT WISH TO SEE and click 'View | Hide Staves'. The unwanted staves will disappear.
When that is done you'll probably want to change the number of systems per page to arrange things neatly. If you want some or all of them back visible for any reason, highlight the systems you want expanded and click 'View | Show Staves'. ALL the staves for those systems will appear.
You may have too fiddle with things a bit to get them the way you want. Try to have ALL the format editing (i.e. number of measures per system, etc.) finished before hiding the staves and changing Systems per Page.
Looks like anaigeon was replying at the same time! Bonjour, Alain!
"We have met the enemy and he is us."
Encore 126.96.36.1996 Win, Windows 7 Pro (7 Home on laptop, XP on an old desktop).
Been using Encore (Rhapsody, Passport) since 1992