Okay, I don't have LightWave in front of me here, so maybe this actually is the answer, but the second question I tried to articulate were how I _make_ the Reference Object that I add to the null? Is this done in the same process?
Ah, sorry. To make the MXS file which will be used by the reference, simply load your mesh (LWO) in an empty scene and use the export button in the Maxwell group. You can reference any MXS file, even files coming from other programs or files which contain multiple meshes. There are no special requirements for referenced files.