adding right and left columns, header to external html

Hi,
How do I add the left, right columns, header, footer templates to an external html page that I would like to link to the opencart site?
It's a separate inquiry form (different from the a contact form) and I created it as a separate page in the 'catalog/view/template/module directory' and linked it to the products page. I tried adding the same php snippets in the layout.php page in to it but it gave an error. Is this possible to do? where else do I need to fix to make it possible? please help.

Thanks & Regards,
Thanushka