[mitiya]

Код:

FOR %%A IN (c d e f g h i j k l m n o p q r s t u v w x y z) DO call :chk %%A
exit

:chk
If Exist "%1:\XPSP3\FINISH\WIN51" attrib +h "%1:\XPSP3\FINISH\WIN51"
goto :eof

как-то так