mod_rewrite to change default root directory

Hi all,

I'm tearing my hair out trying to fix this...

I have a site mydomain.com and would like the default directory to be mydomain.com/site/

My site uses an index.php file to display the correct page. Here's a snippet -

<?php 
	$url = $_SERVER['REQUEST_URI']; 
	$urlend = substr($url, -1);
	if ($urlend != "/") $url .= "/";
	 
	switch ($url) 
	{
	case '/contact/':
			include_once "contact.html";
			break;
	}
?>

Code (markup):

... so this would make the URL appear as mydomain.com/contact/ rather than mydoamin.com/contact.html

This isn't working, I've had it working on another server and now I'm moving stuff to a new one and it's all breaking.

I've created a .htaccess file in the root and this is what it says -

<IfModule mod_rewrite.c>
Options +FollowSymLinks
Options -MultiViews
RewriteEngine On
RewriteCond %{HTTP_HOST} ^mydomain\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.mydomain\.com$
RewriteCond %{REQUEST_URI} !^/site/
RewriteRule (.*) /site/$1
</IfModule>

Code (markup):

This actually works for the index page and loads it as normal along with images, stylesheets etc... but no other pages work )it says the page can't be found.

If I change the .htaccess to this -

DirectoryIndex site/index.html
<IfModule mod_rewrite.c>
Options +FollowSymLinks
Options -MultiViews
RewriteEngine On	
RewriteBase /site/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /site/index.php [L]
</IfModule>

Code (markup):

... then all the pages load correctly (with the right URL) but the stylesheets and images aren't working.

The paths to all assets start with a /
So for example the path to CSS is /css/screen.css

If anyone could help me solve this I would greatly appreciate it! It seems I need a combination of the 2 .htaccess files to get this working correctly.