Integrate elgg site with external pages

Hi all,

I am starting learning elgg and there are a lot of things a don't know how to do at this time. My question is the next:

I want to integrete external pages with my elgg site in order to, for example, have a page with a video or photo gallery keeping the header and footer from de index that i created for de elgg site. This page must be linked with the index page of the elgg site.

I hope i have explained correctly and you can help me.

Thanks a lot.