I use the following diesel expressions to rotate the view, assigned to custom buttons;

Rote VP clock wise 90 degrees,
^C^C_UCS;Z;270;PLAN;;

Rotate VP anti clockwise 90 degrees'
^C^C_UCS;Z;;PLAN;;

They could use a bit of refining...
If you are in model space this macro will rotate the view.
If you are in paper space the ucs rotates, but the view remains the same.
If you are in paper space, in a view port the desired result is achieved.
If the viewport is locked, the UCS rotates anyway, but the view remains the same.

As Long as your operators understand that they must be in the viewport and it must be unlocked, this works great. It will take me a bit more work to make it fool proof...

Suggestions welcome!