Harmony makes a Z-wave controller called the Hub Extender. This can be linked to a harmony Hub and used to control Z-Wave devices from your remote.
However, this Hub Extender has nothing to do with this Harmony Hub Control plug-in. This plug-in only supports Infra Red (IR) controlled devices configured on your Harmony Hub & Remote. You can send IR commands (i.e. remote button presses) to any of the IR devices, and have the Vera respond to Hub Activity changes via scene triggers.
You will not find detailed instructions on the Harmony Hub Extender in this forum.