Create a hash with 19200 entries. The key will be the values you want to have stored in that file and the value will be the filehandle. Then, iterate through your file, parsing each line. Find the filehandle associated with that value and print the line to that filehandle. Something like:

use IO::File;

my %filehandle;
while (my ($k, $v) = associate_filename_with_values())
{
    $filehandle{$v} = IO::File->new(">$k")
        || die "Cannot open '$k' for writing\n";
}

my $data_fh = IO::File->new($datafile)
    || die "Cannot open '$datafile' for reading\n";

while (<$data_fh>)
{
    chomp;
    next unless length $_;
    my @line = split, /\s+/;

    my $value = $line[SOME_INDEX];
    $filehandle{$value}->print("$_\n");
}

$data_fh->close;
$_->close for values %filehandle;
[download]

That code will need some work, especially in associating filename with value, but that should give you a headstart.

Of course, if you want to pay me to write it for you, email me at rkinyon@columbus.rr.com - I charge decent rates for bioinformatics work.

------
We are the carpenters and bricklayers of the Information Age.

The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.