Here is an example you might find useful:

use strict;
use warnings;

# Formats

my ($crt, $text, $num);
format =
  @<  @<<<<<<<<  @###.##
  $crt, $text, $num
.

format STDOUT_TOP =
  @|||||||||||||||||||||
  "Example Format"
  ----------------------
  Nr  Text      Number
  --  --------  --------
.

my $total = 0;
format RAPORT_TOTAL =
  ----------------------
                 @###.##
                 $total
  ----------------------
.

# End formats

while (<DATA>) {
    s /[\n|\r]//g; # clean
    ($crt, $text, $num) = split(/;/, $_, 3);
    $total += $num;
    write();
}

# Change format
$~ = "RAPORT_TOTAL";
write();

__DATA__
1;some data;123.34
2;other;432.54
3;testing;123.55
[download]

Regards, Stefan