3D point series and Z-value visuals

[Morten]

I use a 3D chart via the 3d point series. I want to grasp the Z value in a more quick and informative way. Say the Z-values vary between -100 and 100. Is there any way of illustrating this with reference to zero? I.e. if the Z-value is +80, I want to be able to figure this out quickly by having a blue bar or line going from the "back wall of zero" to the +80 value. A kind of "line" or "arrow" to gauge the depth of Z is what I want, then. In a similar way, if the Z-value is -20, I want to see a small arrow or bar going from 0 and backwards to -20, preferrably in a different colour. Or, as an alternative - is there any way of setting the back wall (Z-wall) at zero, so that I can get 3d points in front of and behind this zero-wall?