What is the best way to make it so that a web application (in PHP) can be installed by someone who doesn't know HTML or any code, and they can use it with their pre-existing design that they have made in Dreamweaver and Fireworks?

For example.
Every page would have the same header and footer, and the PHP part would have to go in the content part of the page. The title and possibly meta tags would also want to be changed. Dreamweaver would make a stylesheet etc.

I've tried templating engines like Smarty in the past, and although they are easy for me, as I have said it is for someone who doesn't know any code, so it's no good.

Is there an elegant way of accomplishing this? So that they can drop the PHP files in, and with minimal setup, get it working with their website?