I actually wrote a perl utility called "resub" (and posted it here that could take a list of file names on stdin, take one or more perl regex substitutions as command line args (or from files named with command line args), and apply the substitutions globally in each file (optionally appending some suffix to each file name when saving new version of each file). Hope that helps.

As for "dir /b/S", personally I prefer to use unix utils that have been ported to windows (e.g. by Cygwin, Delorian or GNU) such as "find", "ls", "bash", etc.