[Closed] custom attributes or something else?

A node is path constrainted to a spline. I’d like to read the percent along path value and do some math on this and then make the result available as a custom attribute (for wiring etc.). I can make the custom attribute but I don’t know how to make it appear when wiring:sad:

I know this code is wrong- just to give an idea of what im trying to achieve

def=attributes test
(

– I need to assign this var to a controller- but I don’t know how
–myVar = $myNodeOfInterest.pos.controller.path_constraint.percent.controller.value * –“some math”
)
b=Box()
custAttributes.add b def