[alpap]

Код:

@echo off
set "Backup=D:\Backup"
set "Months=C:\Months"
set "Decades=C:\Decades"
set "c1=01"& set "c10=10"& set "c20=20"
set "exp=bak"
set "dd=10"

pushd "%Backup%"
 for /f "tokens=1-5* delims=_" %%a in ('2^>nul dir /a-d/b/s "*.%exp%"') do (
  echo %%e|>nul findstr /x /c:"%c1%" && ((if not exist "%Months%" md "%Months%")& >nul copy "%%a_%%b_%%c_%%d_%%e_%%f" "%Months%")
  echo %%e|>nul findstr /x /c:"%c10%" /c:"%c20%" && ((if not exist "%Decades%" md "%Decades%")& >nul copy "%%a_%%b_%%c_%%d_%%e_%%f" "%Decades%")
 )
 for /f "delims=" %%A in ('dir /ad/b') do (
  pushd "%%A"
   for /f "delims=" %%a in ('dir /a-d/b/o-n "*.%exp%"^|more +%dd%') do del "%%a"
  popd
 )
popd
pause