Assign SL Face Numbers to Mesh Object

[Draxamus Eros]

Okay, so I know how to assign material in blender. When I upload to SL, I can manually select the faces on the object and change the texture. However, I'm unable to use a script to change the textures, as they all seem to be considered face 0. Does anyone know how to have more than one face number in a mesh object?

[Chic Aeon]

Likely  you know all this:

Face numbers are determined by the number of materials. So if you have a six sided cube, you wanted a different inworld material on you would select each face in your 3D program and assign a separate material to that face. You can have up to eight materials on one mesh object. Faces are numbered 0-5 in SL with -1 being "all faces".

If you can change the faces manually in world then you should be able to change them with a script. Perhaps it is your script?