finding y on mesh

Use a line pick and then get the y value from pickedy()

linepick entityX(myobject),entityY(myobject),entityZ(myobject),entityX(myobject),entityY(myobject)-5000,entityZ(myobject)
pickedY() should now hold the Y position

edit: oops,... got beat to it. Forgot to mention the mesh needs to be pick-able