> 20110707_algol.dat
dir ::"^201\d{5,5}.*.dat$"
rem shows the file
for %i in (::"^201\d{5,5}.*.dat$") echo %i
rem doesn't show the file
> for /w z in ("::^201\d{5,5}.*.dat$") dir %z
C:\tmp\20110707_algol.dat
C:\tmp\20110708_algol.dat
C:\tmp\20110709_algol.dat
C:\tmp\20110710_algol.dat