$file=c:\kix\kix32.exe
$monthover=0

$date_old=getfiletime("$file")
$year_old=VAL(substr($date_old,1,4))
$month_old=VAL(substr($date_old,6,2))
$day_old=VAL(substr($date_old,9,2))

IF (VAL(substr(@date,1,4))-$year_old)>0 AND ($month_old<12) $monthover=1 GOTO decided ENDIF

IF (VAL(substr(@date,1,4))-$year_old)>0 AND ($month_old=12) AND (@monthno>1) $monthover=1 GOTO decided ENDIF

IF ((@monthno-$month_old)>1) $monthover=1 GOTO decided ENDIF
IF ((@monthno-$month_old)=1) $monthover=1 GOTO decided ENDIF
EXIT

:decided
; "Commands to delete the file here"
EXIT

To read multiple files just do a dir /b in the directory and create a textfile - and read the resulst with a loop.