Near Attenuation/Lens radius of Spotlight

Hello,
Is it possible to set a range for attenuation of a spotlight, both near and far? Attenuation now only seems to affect far, but does affect near attenuation in volume in a non-predictable way. I’d like to set the near attenuation and build as a parameter that links to inner/outer cone angle. Result of this is similar to Arnold’s lens radius function.

Thanks!