How do I 'include' the Zen header on the rest of site?

Hi,,

I have built my site in php with following structure:

Main page: index.php

inside that file i have my php includes that work:

include site_header.htm
include site_footer.htm
etc.....

The Zen store is installed in a folder: /registration

My other non-store pages will be:
https://www.mydomain.com/about
https://www.mydomain.com/contact

and so on and so forth... I prefer to use short urls. But I want to have it so the user can login from any page and if they log in, that header file will show that they are even though they are visiting non-store pages on the site... Is this possible to 'include' the zen header file on non-store pages...

I've tried a couple different includes on my non-store pages and used the path directly to: /registration/includes/templates/mycustomtemplate/common/tpl_header.php

No such luck though..

I don't want to do it the other way around whereas in the past I've customized the include files and added a flash menu,slide show,,etc to the store...

Thanks in advance....

You'll be much better off if you allow Zen Cart to run the entire site. If you link to pages outside of Zen Cart, your customers will lose their sessions when they move back and forth.