OK, at the present time the smartthings zwave implementation does not technically support zwave central scenes.
So what your DTH has to do is to convert The central scene codes into “button presses“ and present itself to smart things as a button controller. So if your device supports 12 different central scene numbers then it would look to smartapps, including the official smart lighting feature, like you have 12 buttons.
You can see examples of this in the custom code handlers for the Homeseer switches, for example.