Installing in a subdirectory; no admin access

The ISP requires the WP files to be installed in a subdirectory /public/www.

I can access the website http://www.townsendsport.com but when trying to access the site admin http://www.townsendsport.com/wp-admin/ I receive an error message

Warning: require(./public/www/wp-admin/index/wp-blog-header.php) [function.require]: failed to open stream: No such file or directory in /web/sites/user/2/192/162818/public/www/wp-admin/index.php on line 17

Fatal error: require() [function.require]: Failed opening required ‘./public/www/wp-admin/index/wp-blog-header.php’ (include_path=’.:/usr/share/php:/usr/share/pear’) in /web/sites/user/2/192/162818/public/www/wp-admin/index.php on line 17

I have modified the index.php in /public/www/wp-admin/index.php to the following;

<?php
/**
* Front to the WordPress application. This file doesn’t do anything, but loads
* wp-blog-header.php which does and tells WordPress to load the theme.
*
* @package WordPress
*/

/**
* Tells WordPress to load the WordPress theme and output it.
*
* @var bool
*/
define(‘WP_USE_THEMES’, true);

/** Loads the WordPress Environment and Template */
require(‘./public/www/wp-admin/index/wp-blog-header.php’);
?>

Where am I going wrong please?