use strict;
use warnings;
use Spreadsheet::WriteExcel;

my $file = "test.xls";
my $xWB = Spreadsheet::WriteExcel->new($file);
my $xWS5 = $xWB->add_worksheet('Summary');

my $format = $xWB->add_format();
$format->set_bold();

my $row_count = 5;
my $multiply = $xWS5->store_formula("=E2*F2");

for my $line (0..$row_count) {
	$xWS5->repeat_formula($line, 6, $multiply, $format, "E2", 'E'.($line + 1), "F2", 'F'.($line + 1));
}