select them from the data meshes dir in the morrowind CS cd (the other one your not prompted to put into the cd drive during install) this is the use for.
the data dir on that cd is esentualy the BSA file extracted and left in order so when you pick a file from there it also points to the bsa file that was installed thus you dont need to copy any of these files over as it already has access to them you just cant look at them with any degree of comfort the CSCD has it set out all nice for you and that should be that (also the expansions also have all there bsa files expanded for you in the same maner on the one cd)
hope this helped or made sence