Short answer is I got someone smarter to handle it.
the registration is tidied up by reading the ARToolkits camera parameters file and using the lens distorion info to bend a mesh around before sticking the 'real' image onto it as a texture.
the matrix is translated into rotations and translations in degrees in the tracking program before feeding it into touch. owever, if you look in any null or geometry component, you can see a pre-transform tab which has a 'matrix chop' input' that lets you use a chop to feed in the 4 x 4 matrix. ARToolkit only needs 4 x 3 but same thing. you should be able to feed it to a chp then to the pretransform chop field.