One WordPress install serving multiple virtual hosts

I have a number of WordPress-enabled sites setup as virtual hosts under XAMPP on a Windows 7 development server.

An example virtual host is as follows:

<VirtualHost *:80>
ServerName siteA.localhost
DocumentRoot “C:/htdocs/siteA”
</VirtualHost>

My goal is to have all the sites use the same WordPress install, which is located in it’s own folder off the Document Root, ie: “C:/htdocs/wordpress”.

The only WordPress files unique to each virtual host will then be the wp-config.php file and the /wp-content/ folder, which will be located off the root of each site.

Does anyone have any suggestions for how to achieve this? I’ve tried adding the WordPress folder as an Alias for each Virtual Host, and adding it as “php_value include_path” value for each Virtual Host as well, but neither of these have worked.

Ultimately I want to make it easy to upgrade all my WordPress-powered sites by having them share the same WordPress core.

Thanks.