After playing around for a while I’ve managed to get the game to launch.
Start VorpX.
Go to the taskbar and right click on the Vorpx icon.
Select “create desktop short cut” and select the location of the Witcher 3 exe
Run W3 from the shortcut.
Now I’ve got other problems.
The FOV is all wrong.
The scenery warps and bends with camera movement.