use strict;
use warnings;

my @wanted = qw{ 55 48 22 };

while ( <DATA> )
{
    my( $head, $tagStr ) = m{ (.*) \s+\x5b ([^\x5d]+) }x;
    print qq{Line      : $head\n};

    my %tags =
       map { split m{=} }
       split m{\x01}, $tagStr;
    print
       qq{Tags found:\n},
       map  { sprintf qq{            %-3s => %s\n}, $_, $tags{ $_ } }
       sort { $a <=> $b } keys %tags;

    print
       qq{Wanted    : },
       join q{|},
          map { exists $tags{ $_ } ? $tags{ $_ } : q{} } @wanted;
    print qq{\n===========\n};
}

__END__
2009/01/15 01:23:45:678: ASDF: [8=FIX.4.4
9=228
35=D
49=ZYXW
56=MYCO
34=6
52=20090115-01:23:45
116=BLAH
129=HALB
50=MEH
1=HEM
11=abcefg123456
15=ZZZ
21=1
22=5
38=100
40=2
44=4.80000000
48=ZVZZT.N
54=2
55=ZVZZT
59=0
60=20090115-01:23:45
100=MEH
10=111
]
2009/01/15 01:27:09:154: QWER: [8=FIX.4.4
9=228
35=D
49=ZYXW
56=MYCO
34=6
52=20090115-01:23:45
116=BLAH
129=HALB
50=MEH
1=HEM
11=abcefg123456
15=ZZZ
21=1
22=5
38=100
40=2
44=4.80000000
54=2
55=ZVZZT
59=0
60=20090115-01:23:45
100=MEH
10=111
]