You will need a special Audio Aux Link cable. See: http://forum.beoworld.org/forums/thread/101338.aspx
BM7000 BS9000
Pin 2----------------------Pin 2
Pin 1----------------------Pin 3
Pin 4----------------------Pin 5
Pin 3----------------------Pin 1
Pin 5----------------------Pin 4
Thanks to Søren...
Main difference is you don`t have a BS 7000 but a BC 9300.
You can listen to whatever is activated on the BC 9300 by pressing A.AUX on the BS 9000.
Hope this helps.
Stefan