Thanks for the help, you've got me pretty close to what I want, but it's not quite there.
I have a 2 disc album (Dynamic Stillness) that's made up 2 long tracks, one on each disc.
I have the main panel set to the Album Art view, when I apply the Disc-Track# rule to the information shown in the Expanded Panel it displays the information like this...
1 Dynamic Stillness Part 1
1 Dynamic Stillness Part 2
To me it would make more sense, and it would be "cleaner," to display the information as...
1.01 Dynamic Stillness Part 1
2.01 Dynamic Stillness Part 2
I'm guessing it's not possible; it's a real shame because MusicBee has such a clean, configurable, minimalist interface, it's one of the reasons I started using it after looking at foobar, JRiver etc.