use Spreadsheet class to export excel with PHP
File list:
Spreadsheet
..........\Excel
..........\.....\Writer
..........\.....\......\BIFFwriter.php
..........\.....\......\Format.php
..........\.....\......\Parser.php
..........\.....\......\Validator.php
..........\.....\......\Workbook.php
..........\.....\......\Worksheet.php