[Petya V4sechkin]

Код:

@Echo Off
SetLocal EnableExtensions EnableDelayedExpansion

Set SrcDir=D:\work
Set OutFile=D:\MyDir.txt

Set FirstChar=A
Set LastChar=L

Del /F /Q %OutFile% 2>nul
For /F "Delims=" %%I In ('Dir /AD /B %SrcDir%') Do (
  Set C=%%I
  Set C=!C:~0,1!
  If /I !C! Geq %FirstChar% If /I !C! Leq %LastChar% (
    Echo %SrcDir%\%%I>>%OutFile%
  )
)