material instances

When I add a material as an instance to a multi\sub object material group, the instance is exported as a copy.
This is how it names the material, "material object_1_name/Freeroam-Billboard", "material object_2_name/Freeroam-Billboard" I need it to be just "material Freeroam-Billboard". How can I get it to be an instance ?

Thanks

The same material is assigned to all instances?

I am putting name tags above some characters in a scene using 3d geometry, the name tags all use one material with the names written on its texture. The name tag and its character are one mesh.

Each character has a Shell Material used for the lightmaps,
the Original Material and Baked Material slots have a Multi/Sub-Object in them,
for each character I have added an instance in the last ID slot of the Multi/Sub-Object material.

When I export the exporter adds the name of the Multi/Sub-Object in front of each of its materials.
In most cases this would not be a problem, but as I need one of the textures to be an instance I need to be able to not have the Multi/Sub-Object name added to the material name.

If I leave the Multi/Sub-Object name as blank then I get the result I want, but 3DSMax doesn't like this and makes up a name in the blank slots every time I reopen the file.
Could you add an option in the exporter to not include the Multi/SubObject name in front of the
sub-material names in the material file or tell me how to do so if this is already implemented.

This will be a common problem, as Multi/Sub-Object groups of materials are often used in 3ds max for tidiness, to not fill the Material Editor slots and Max turns the materials of an object into a malti/Sub once they are deleted from the mtl/map editor slots.