If you use BX CSS Expansion from the Brawlex thread's original post, you can add BX characters to random in CSSRoster.dat. This file replaces the functionality of custom CSS and custom random codes.
The Brawlex config utility can help with editing CSSRoster.dat. Simply increase the number of available icons to the amount you want (max 100) and assign the ID number to CSSSlot##.dat's number. The ID to call random should be placed here too. Then repeat the same thing for the random list (minus the random ID, as random shouldn't be calling random).
I understand the first part (as it is what I do) but I don't understand the random list part ^^;Never mind I figured it out, thanks!