dynamic subdomains in Symfony 1.4

I am trying to create d开发者_Python百科ynamic subdomains in .htaccess. I want something like this:

http://ladygaga.koncert.com  --> http://koncert.com/concerts/ladygaga

kris wallsmith published something in the symfony blog, about subdomain routing in sf1.2. maybe this helps you: http://symfony.com/blog/call-the-expert-adding-subdomain-requirements-to-routing-yml