use strict;
use warnings;
use autodie;

my $input = 'D:/Some/Specific/Path/To/Input.CSV';
my $output = 'D:/Some/Specific/Path/To/Output.CSV';
open IN,$input;
binmode(IN);
open OUT,'>'.$output;
my $count = 0;

while (my $line = <IN>) {
	chomp $line; # good practice?
	next if $. < 2; # do not need first line
	my @fields = split ";" , $line; # define input-lines
	my @vk = $fields[1]; # extract all VK-codes
	my %seen; # declare hash to 'memorise' which VK has already been pushed
	my @uniq; # declare array to store unique values
	for my $vk (@vk) { # need to 'check' all VK-codes in @vk
		push (@uniq, $vk) unless $seen{$vk}; # only push VK-codes that are not yet pushed
		for my $uvk (@uniq) { # uvk = unique VK
			if ($count != 10) { # we want 10 VK-codes per line -- works as intended
				print OUT $uvk.';';
				++ $count;
			} else {
				print OUT "\n";
				$count = 0;
			}
		}
	}
}

close IN;
close OUT;
exit 0;