As requested, this is just a starting place based upon the information you've provided and testing is limited to exactly that shown in the output. You'll probably want to tweak the regex to better match your data.

In terms of performance, I tested it against 10 years worth of monthly files with 100 comments per file, which I think far exceeds your requirements, and it takes all of 6/100ths of a second. That's probably how long it would take to make a connection to a database.

#! perl -slw
use strict;
use Time::HiRes qw[ time ];

sub slurp {
    local( $/, @ARGV ) = ( -s( $_[0] ), $_[0] );
    <>;
}

my $start = time;

my $user = $ARGV[0] or die 'No user supplied';
my @matches;
my $files = 0;
while( glob 'hist/*.htm' ) {
    $files++;
    my $file = slurp $_;
    push @matches, $_
        if $file =~ m[
            <b>Comment\s+\d+</b><br>\n
            \Q$user\E
        ]mx;
}

printf "Searched $files files in %g seconds\n", time() - $start;
die "No match found for user $user" unless @matches;
print "User $user found in files:\n", join "\n", @matches;

__END__
P:\test>522029 Buk
Searched 133 files in 0.0694289 seconds
No match found for user Buk at P:\test\522029.pl line 26, <> line 133.

P:\test>522029 Doug
Searched 133 files in 0.069006 seconds
User Doug found in files:
hist/h0511.htm
hist/h0601.htm

P:\test>522029 "J H"
Searched 133 files in 0.0696189 seconds
User J H found in files:
hist/h0511.htm
hist/h0601.htm
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