chops.png attached as ref.

in this network, Points is referring a CARVE node outputting an animated position along a path.
I can setup an UP attribute in this node, but I am not sure how to pass it to, say, the 3rd input on a constraint look at node.

Currently, I am delaying (delay node) the output from the Points and used this as 3rd input.

the goal is just to keep the UP based on the closest tangent of the path.

If everything goes wrong? how do I build myself a custom UP vector in chops?