htaccess redirect to subdir

[#1]

I have the following code in my .htaccess file located in my /public folder
RewriteEngine on
RewriteCond %{HTTP:Host} ^(?:www.solareclipse2015.org.uk)?$
RewriteCond %{REQUEST_URI} !^/wordpress/
RewriteRule ^(.*) /wordpress/$1 [NC,L,NS]
Its working fine when www.solareclipse2015.org.uk is entered in a browser, however http://solareclipse2015.org.uk (without the w's) is not redirecting. Does anybody know how I can fix this?
Regards

[#2]

That .htaccess code checks for either the complete www.domain or an empty host string
Adapting this one, based on Gabe's post here, should meet your needs. This makes any subdomain optional.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^([^.]+\.)?yourdomain\.co\.uk$ [NC]
RewriteCond %{REQUEST_URI} !^/yoursite/
RewriteRule (.*) /yoursite/$1 

[#3]

That works! Grea thanks