6-axis rotation with a 2-axis device

[micheus]

Ok, you are talking about the camera rotation and not object rotation. Right?

The camera can only be moved in the standard axis. There is no Roll option (although it seems to be an interesting option):

(source: wikipedia)

For objects, you can define an Default Axis that can be used in commands like Move and Rotate (for that option) - its is found at Tools menu.