use HTML::Template;
my $template = HTML::Template->new(filename => "test.tmpl");

my @data = (1 .. 30);
my $items_per_row = 5;

my $x = 0;
my @loop;
foreach (@data) {
    my %row = ( data => $_ );
    $row{break} = 1 unless $x % $items_per_row or $x == 0;
    push @loop, \%row;
    $x++;
}
$template->param(loop => \@loop);
print $template->output();