...

use strict;
use warnings;
use DBI;
use POSIX;
use File::Basename;
use Net::SFTP::Foreign;
use Text::CSV::Simple;
use Spreadsheet::WriteExcel;

...

# Generate XLS from array:
my $strExcelFilename = "filename.xls";
my $workbook = Spreadsheet::WriteExcel->new($strExcelFilename);
my $worksheet = $workbook->addworksheet("worksheetname");
my $intStartRow = 1;
my $i = $intStartRow;
my $intQueryArray = 0;
my $o = $intQueryArray;
my $intStartCol = 0;
my $u = $intStartCol;

$sth = execute_query("QUERY THAT RETURNS DATA FOR MULTIPLE COLUMNS IN ONE COLUMN");

my %header = (
-bold => 1,
-italic => 1,
-text_wrap => 1,
-border => 1,
);

my $format = $workbook->add_format(%header);
$worksheet->write('A1', "something", $format);
$worksheet->write('B1', "something", $format);
$worksheet->write('C1', "something", $format);
$worksheet->write('D1', "something", $format);
$worksheet->write('E1', "something", $format);
$worksheet->write('F1', "something", $format);
$worksheet->write('G1', "something", $format);

# Format and split strings from query into their corresponding columns
my @res;

while ($res[$o] = $sth->fetchrow_array()) {
	my $set = $res[$o];
	$set =~ s/[\(\)]//g;
	my @values = split(',', $set);
	
	foreach my $value (@values) {
		$worksheet->write($i, $u, $value);
		$u++
		}
		
	$u = 0;
    $i++;
	$o++;
}