To Control Automatic Layer Assignment
Using the ecad_hint.map file, you can specify an overriding mapping (over the automatic mapping) to produce a new ECAD_<mapped name> layer. The component is placed in that layer:
map_objects_by_name->
ECAD_NAME "eesmb"
ECAD_ALT_NAME "DM7442N"
ECAD_TYPE ""
MCAD_NAME "EESMB_DM7442N"
MCAD_TYPE "part" 
MCAD_LAYER "<ANY>
* 
The ecad_comp_layer_map preferences option must be set to yes.