#!/usr/bin/perl
use strict;
use warnings;

use Text::CSV;

die  "Usage: $0 <filename>\n" unless @ARGV > 0;
open (my $fh, '<', $ARGV[0]) || die "$ARGV[0]: $!\n";

my $csv = Text::CSV->new();

$csv->eol("\n");

my $sum = 0;
while (my $row = $csv->getline( $fh )) {
    $sum = $row->[3];

    if ($sum > 310) {
      $row->[3] = 'volemd';
    }
    elsif ($sum == 70) {
      $row->[3] = 'volemd1';
    }

    $csv->print(\*STDOUT, $row);
}
$csv->eof or $csv->error_diag();

close ($fh);