On windows hosting you cannot install an application on the main domain i.e. domain.com cannot have an application install on it. Application has to be installed on e.g. domain.com/wordpress.
A .php redirect can then be added to the domain's root folder and point it towards the application vault install. To set up a redirect using PHP ; create a file called index.php in the root folder and insert the following code:
header( 'Location: http://www.yourdomain.com/new_page.html' ) ;
Where yourdomain.com/wordpress should be replaced by the location you want the script to redirect users to.
The above is an example of a 302 redirect. If you wish to use a 301 redirect, please use:
header('HTTP/1.1 301 Moved Permanently');
You will also need to add index.php to the list of default documents under:
Websites >> domainname >> Website Configuration >> Default Documents