Javascript on precomped layer


I’m making a project for motion capturing.
This project has many scenes with differnt effects, so I made many layers and zapping them by Layer Precomps.
each layer embedded a Javascript for GetWorldPosition of motion traced Objects.
When I precomp a layer, Javascript that embedded on layer doesn’t work.
Another way, I made script to get WorldPosition of nodes on another layer, it doesn’t work too…

How can I work Javascript on precomped layer?
or, How can I get WorldPosition of node on another layer?