If you want to use a MIDI controller that is not yet supported and, for this reason, has no script, you must first add a new MIDI controller surface for it.
Prerequisite
If you have previously used an earlier version of Cubase, and if you already set up your MIDI controller using Generic Remote, Track Quick Controls or VST Quick Controls, open the Studio Setup dialog, open the MIDI Port Setup page, and set the corresponding MIDI ports to Not Connected. This ensures that no double mappings occur when the MIDI Remote functionality automatically detects those MIDI controllers on connection.
Procedure
Result
The MIDI Controller Surface Editor opens in the lower zone of the Project window. Here, you can edit the controller surface.