The more and more i think about your problem (and i still don't know exactly what you are trying to do), the more and more i feel you should be using DBD::CSV. Why? Because your data files are CSV and you are reporting on them, and when it comes to reporting, SQL is quite nice.

use strict;
use warnings;

use DBI;
use File::Basename;

my @stuff;
my $file  = 'sfoct01.txt';
my $table = (fileparse($file,'.txt'))[0];
my $dbh   = DBI->connect(
   "DBI:CSV:f_dir=.;csv_eol=\n;csv_sep_char=,;",
   {RaiseError=>1},
);

$dbh->{csv_tables}->{$table} = { 
   file      => $file,
   col_names => [qw(account amount)],
};

my $sth = $dbh->prepare("
   SELECT account,amount 
   FROM $table 
   ORDER BY account
");
$sth->execute;

while (my ($account,$amount) = $sth->fetchrow_array()) {
   @stuff = ($account, $amount, 10, 10 - $amount);
   write;
}



format STDOUT_TOP =
+-----------------------------------------------------------------+
|                           Monthly Recap                         |
|----------------------------+----------+-----------+-------------+
|Account                     | Prior    | Current   | Difference  |
|----------------------------+----------+-----------+-------------+
.

format STDOUT =
|@<<<<<<<<<<<<<<<<<<<<<<<<<<<|@#####.## | @#####.## | @#####.##   |
@stuff
|----------------------------+----------+-----------+-------------+
.


__END__
yields:
+-----------------------------------------------------------------+
|                           Monthly Recap                         |
|----------------------------+----------+-----------+-------------+
|Account                     | Prior    | Current   | Difference  |
|----------------------------+----------+-----------+-------------+
|Bam bam                     |     5.00 |     10.00 |      5.00   |
|----------------------------+----------+-----------+-------------+
|Betty                       |   300.00 |     10.00 |   -290.00   |
|----------------------------+----------+-----------+-------------+
|Wilma                       |   200.00 |     10.00 |   -190.00   |
|----------------------------+----------+-----------+-------------+
|barney                      |    30.00 |     10.00 |    -20.00   |
|----------------------------+----------+-----------+-------------+
|fred                        |    10.00 |     10.00 |      0.00   |
|----------------------------+----------+-----------+-------------+
[download]

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)