URL - Rewriting and showing the clients dynamic websites

I am creating an website that will allow users too create there own blog/Content to there website. and depending upon there keyword their website will be created, same as blogspot.

So how can i redirect/show the client website when anyone enters the url such as http://www.c开发者_运维知识库lientid.xyz.com/

where my website will be www.xyz.com.

Moreover i have an shared server, i was not achieve this in shared server, so can i achieve this? and if yes then how can I?

Thanks

What's normally referred to as URL rewriting does not work with domains. It only works with subdirectories and pages within the domain.

You need to be able to modify your domain records. This is not a C# issue, it's a domain control issue. And I seriously doubt you'll have that control on a shared hosting account.