>>272 こんな感じかなあ

 @echo off
 setlocal ENABLEDELAYEDEXPANSION

 for /F "tokens=1* delims=," %%I in ( 'dsquery user -samid %usernam%' ) do (
  set HEAD=%%I
  set TAIL=%%J
  :LOOP
  if "!HEAD!" == "" goto :NEXT
  for /F "tokens=1* delims==" %%I in ( "!HEAD!" ) do (
   if "%%I" == "CN" set CN=%%J
  )
  for /F "tokens=1* delims=," %%I in ( "!TAIL!" ) do (
   set HEAD=%%I
   set TAIL=%%J
   goto :LOOP
  )
  :NEXT
  echo.!CN!
 )