http://fox.wikis.com/wc.dll?Wiki~RecursiveDirectoryProcessing~WIN_COM_API
NB: recursive function in VFP hangs time to time(stack overflow...).

update:
*can also try this link (pinted in the url above: http://www.news2news.com/vfp/?example=236&function=378

*can also use DOS command: DIR (see help in http://ss64.com/nt/dir.html.
Can build a bat file and execute it as follow.its very fast.

set defa to addbs(justpath(sys(16,1)))


local m.myvar
text to m.myvar textmerge noshow
  dir "<<justpath(getd())>>" /a-d /b /s > yfilename.txt 
endtext
set safe off
strtofile(m.myvar,"ydir_dos.bat")
*modi comm ydir_dos.bat

local oshell
oshell=newObject("wscript.shell")
oshell.run('ydir_dos.bat',0,.t.)
oshell=null


run/n notepad  yfilename.txt