I have a feeling that this isn't possible, but I'll ask the question
anyway. Is there a way to lock cells but allow certain information to
be entered or changed, but not other information. For instance if the
possible entries into the cell are A, B and C, is it possible to allow
anyone to enter A or B, but only users with a password to enter C.

If this isn't possible using cell locking, is there another way to
work around it? Any help is greatly appreciated.