The VRC0P buttons are “virtual” and allow the RF Toolkit to assign an area to a particular button. The software is then nice enough to synchronize this information back into the VRC0P.
The Vizia RF + Installer Toolkit documentation "Association Management" -> "Associations" online help provides a good amount of detail. I have found that you should start of creating rooms with all your lights. You can then create an “area” from a room. This area can then be assigned to a any zone controller button (i.e., VRC0P virtual buttons).
I believe area identifiers match the numeric order on VRC0P buttons.
If a Z-Wave device is scene capable, you can configure different brightness and off/on preset using RF Installer Toolkit.