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

my $file = "/path/to/file/";
my $xWB = Spreadsheet::WriteExcel->new($file);
my $xWS5 = $xWB->add_worksheet('Summary');

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

#DBI stuff here..

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

# write worksheet
my $rowz = 0; my $colz = 0;
$xWS5->write($rowz,$colz++, $_) for @{$sth->{NAME}};

while (my $ar = $sth->fetchrow_arrayref) {
        ++$rowz; $colz = 0;
        $xWS5->write($rowz, $colz++, $_) for @$ar;
for my $line (0..$row_count) {
#this arguments are row, column, formula, format, first cell, second cell
     $xWS5->repeat_formula($line, 6, $multiply, $format, "E2", 'E'.($line + 1), "F2", 'F'.($line + 1));
     }
}