Pretty sure Judith gave a review of her difficulties with the company/device mentioned above.
The simplest (but not most economical) solutions are:
1/ consider a BeoPort, or
2/ invest in a Beo6 (not sure of its range)
assuming of course that you have some form of a masterlink or Beolink Wireliss setup in place ...
Now I have reread the OP I wish I could delete my response :-)
my Apple Airport express connected Beosound 8 located downstairs
So now I am not sure what is the best approach for you ... do you have anly plans to expand your B&O equipment in the future ?
And if not, do you have an iPad, iTouch or iPhone that you can use the Remote app on to provide remote control wirelessly up to the iTunes that will then broadcast the sound wirelessly back down to the Airport Express/BS8 combo ....
First B&O (1976) was a Beogram 1500 ... latest (2011) change has been to couple the BL11 with the BL6Ks *sounds superb*