2 Main files you will need to edit are
3DEffect.ini
Action3DEffect.ini
You will then also need to add any new textures/mesh files to the following
3DTexture.ini (Textures)
3DEffectObj.ini (Mesh)
Please note you will need UNIQUE IDs in both files.
Also it might help to know that Action3DEffect is like the 3Dmotion of the effect class and 3dEffect.ini is like the 3dSimpleObj.
Hope this helps. Give it go before you try having us expalin it all