Hi, There isnt a menu for the STB controller on MXs, its done by using the tune button under v-setup on a Beo4 with the appropriate set top box IR number from the exact B&O Table/Chip STB List.
You must find out what B&O Table/List chip is installed before you can programme it or buy the new chip which is at the moment for the UK 4.18 with support for newer boxes!
regards Douglas
p.s on the back of TV should be a sticker with STB table number, with this number you can get the box list from your dealer & then programme the controller.
Hope this is clear enough