Sub Domain redirection with .htaccess

[eluser]Phil Sturgeon[/eluser]
Ok so this isnt STRICTLY a CI question, but its a question people can use with CodeIgnitor...

If I have

http://john.doe.example.com

how can I make it go to

http://example.com/controller/method/john/doe/

Before you say "Duh use mod_rewrite", dont. have been trying loads of rules for ages, so while mod_rewrite is the answer, its not particularly easy.

[eluser]esra[/eluser]
I'm not sure if this will help in your particular case:

http://ellislab.com/forums/viewthread/47523/

[eluser]Phil Sturgeon[/eluser]
Closest I can get with links from that topic is:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^www\.[^.]+\.kicknote\.com$
RewriteRule ^(.+) %{HTTP_HOST}$1 [C]
RewriteRule ^www\.([^.]+)\.([^.]+)\.kicknote\.com index.php/mocknews/article/$1/$2

And it doesnt work...