Albert, to change the perspective of the cuboid add the following directly after the calculation for the nXdis and nYdis values and before the actual drawing commands:

* To change the perspective of the cuboid change the sign of nXdis and/or nYdis

nPerspective = 1

DO CASE
CASE nPerspective = 1
  
  * Up and to the right

  * Leave as is as that would be the default.
  
CASE nPerspective = 2

  * Down and to the right
  
  nYdis = nYdis * -1
  
CASE nPerspective = 3

  * Down and to the left
  
  nXdis = nXdis * -1
  nYdis = nYdis * -1
  
CASE nPerspective = 4

  * Up and to the left
  
  nXdis = nXdis * -1
  
ENDCASE