Let's see what I can do...
http://dungeoncraft.forumsplace.com/post-207.html#207
You can just use this config.txt (it's at the very bottom) in place of the current one.
There are two ways to change the config.txt to make this work. 1~ replace an existing wall format OR 2~ adding to existing walls.
For 1 = Make sure the format number is changed to the one that you are replacing.
e.g. A4_WALL_RECT = 2,2,66,213 // 4 is the format number and would be changed to 3 or 2 or whatever number it is replacing.
For 2 = add at the end of the wall section and make sure the format number is one higher than the last one present i.e. 4 if there are 3 alternative walls. You also must change this line ->
MAX_ALTERNATE_WALL_FORMATS = 4 // 4 is the number of alternative walls and would include the one you have just added.