I am stuck.

I am trying to redirect every broken link and missing page to my homepage.
There is a lot of sub domaind been indexed previously and becuse it was an ex p0rn site they used click tracking with usernames.

this is what i have but it is wrong

RewriteEngine on
RewriteCond %{HTTP_HOST} ^syndk8.net.x$ [OR]
RewriteCond %{HTTP_HOST} ^www.syndk8.net/x/$
RewriteRule ^(.*)$ ************************ [R=301,L]

I am trying to redirect

Ironically there is a mod rewrite tutorial on the site but i have got myself tied up in knots so i need a fresh eye.
I am sure one of you seo wannabe hacks will know straight away