Tim:
They can be loaded via the Materials... dialog box when set to LightWorks Rendering Engine > Load Settings from Archives (these same type of files that are in the ArchiCAD Library 14 > Lightworks 14 folder). These will only effect the materials in a LightWorks rendering. As Dwight has pointed out, the implementation of LightWorks in ArchiCAD is incomplete, so I don't know if any/all of the settings in these files will carry through to ArchiCAD.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David