Mxa - spline creation

[VRT_JPRLisbon_]

hi , the mxa splines are coded , any one know how to uncode it to just numbers and code it again after edit ? 
well im asking this because im doing a track that have the dispmap+perimetre map , i would like to edit the spline by hand with the help of paintshop pro x,z nº´s  of the dispmap+perimetre or the textures (better) or what ever nº´s the spline use (x and z) .

thanks.