use strict;
use warnings;
use Text::CSV;

my @data;   # 2D array for CSV data
my $file = 'AMS.csv';

my %dept_code = (          ###
  1001 => 'IT',            ###
  1002 => 'HR',            ###
  1003 => 'PURCHASING',    ###
);

my $csv = Text::CSV->new({ binary => 1, quote_null => 0 });
open my $fh, '<', $file or die "Could not open $file: $!";

while( my $column = $csv->getline( $fh ) ) {
  push @data, $column;
}


open $fh, ">:encoding(utf8)", "PPS.csv" or die "PPS.csv: $!";
for (@data) {
  $_->[0] += 2000;                    ###
  $_->[7] = $dept_code{$_->[7]};      ###
  $csv->print($fh, $_);
  print $fh "\n";
}
close $fh or die "PPS.csv: $!";