This is an interesting option. As a matter of fact I do have a website for which I would like to include headers & footers on each page, without having to edit each and every page if I add something to the header.
I am renting webspace at a commercial host. It is a Linux system, and it uses Apache, however I don't think I actually have access to the Apache config files. I just rent hosting space, no dedicated server or so. (doteasy.com)
Or is it usual with those commercial hosts that you have a personal config file somewhere? I never tried funny things, because usually I break something. Which is no problem on one of my own machines, but certainly on some remote machine.