You have to use the 'All' xlsm file (--> 'generate all') to generate txt files from the xlsm files. Or you can generate a txt file for one specific xlsm file as Cadmus88 describes in my guide here:

http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=582571#Post582571


My mods for DOS 1 EE: FasterAnimations - QuietDay - Samaritan