I've just got a Wacom 3D pen for sculpting in blender and in the video Wacom released for the pen it shows you can navigate without using the keyboard:
https://www.youtube.com/watch?v=tcIVpiK3TXw
The first button is rotating the view like the middle mouse button and the second one in set for pan/zoom. Now, it is zooming when you click the button and move your hand while hovering over the screen, and the dragging, as the video suggests, is supposed to happen when clicking that button and tapping the screen with the pen tip.
The problem is that it is not dragging (or panning). (I cant find anywhere in the Wacom settings to control the hover and click/touch and click gestures)
Also, it is not a special feature for the 3D pen, it should work like this with all pens (it is working as shown in the video in Solidworks with the default settings).