I downloaded the Norfolk and Western coal hopper. It looks great but is not interactive. Is there a way to make it interactive? Maybe it is not possible but I would like to do it if it is.
A) It has the queues-table in the config.txt file.
B) For a coal hopper, it has a load mesh.
If it has both these, then just add the industryobjecticon to the config.txt file.
But by the sound of what your saying it might not have the queues-table and the load mesh, to check this, if running TRS2006 just start CMP select the coal hopper and right-click select View config.txt file, it will tell you.