I'm new MantisBT user and begginer in PHP/Mysql codes, so please...be patience

1 - I need to create a Excel Icon in print_all_bug_page.php file. How to do it? To create a same Excel report in excel_xml_export.php
2 - I need to customize this Excel report created. I need to add a Header with logotype, address, user login (Who create the Excel report) and other personal columms. Is it possible?
Please, see images below.
Thanks in advance