Targeting a Light at a 3D layer

I wanted to target a light at a layer, so I used the pickwhip to substitute the layer's position for the lights POI.

This worked fine.

However, I wanted greater control, and the ability to fine-tune and otherwise animate the lite's target, so I did something that would work perfectly in my 3D app, but doesn't in AE:
I created a Null, and parented it to the moving layer.
I pickwhipped the Null's position the same way I did before, for the lights POI position.

Sadly, this did not work. In 3D terms I need the 'world coordinates' of the null, not the keyframed coords, since they just sit at 0/0/0.

How can one get the light to follow the NULL, with the null parented to the moving layer?

Suggestions?

Thanks.

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"Putting the HARM in 'harmonica' since 2005."
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Will do, thanks for the suggestion!

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"Putting the HARM in 'harmonica' since 2005."
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