This function was created before GenPath and may be helpful to those who do not have it.
It is useful to put this function in your STARTUP.M file, so you can automatically add direcories to your path when you launch MATLAB. This way, even if your directory structure has changed, you will still include all your m-files.
I was not able to run this on Matlab 6.1, so Release 5.2 seems to be an error. Matlab 6.5 has regexp, but one which doesn#t support 3 argins.
Nevertheless the mfile is very simplistic, all subdirectories are used, but only the first level of a possible tree, and certain directories like @ or private or ., .. are included.