my $dom      = qr{0[1-9]|[12][0-9]|3[01]};
my $month    = qr{0[1-9]|1[012]};
my $fourYear = qr{2003};
my $twoYear  = qr{03};

my $MMDDYYYY = qr{$month$dom$fourYear};
my $DDMMYYYY = qr{$dom$month$fourYear};
my $YYYYMMDD = qr{$fourYear$month$dom};
my $DDMMYY   = qr{$dom$month$twoYear};
my $MMDDYY   = qr{$month$dom$twoYear};
my $MMDD     = qr{($month$dom)};
my $DDMM     = qr{$dom$month};

my @date_regexes = (
  $MMDDYYYY, $DDMMYYYY, $YYYYMMDD, $DDMMYY, $MMDDYY, $MMDD, $DDMM,
);

my $line =
  'F111406585_D072203_B085_E087_T047-P085_FCC_07222003_539.cdr';

print "date is - ", match_precedence(\@date_regexes, $line), $/;

sub match_precedence {
  my($regs, $str) = @_;

  for(@$regs) { return $1 if $str =~ /($_)/ }

  return;
}

__output__

date is - 07222003