In CED Modeling the menu for a 3D Curve -> Spiral 3D/Helix has 3 types, Helical, Conical and Planar as a pull down in the same menu.
For the Helical option, there is a 'Right Handed' option, but for the Conical helix, this is not available - can it be added as per the Helical curve*.
NOTE: There is a workaround, by reversing the axis direction and set the pitch to -ve values - but it seems that this could be achieved within the menu, and that the functionality is already there!
