IIS Subdomain

Question

Greetings,
I want to create a subdomain programmatically.
Means from the page http://www.somesite.com/createdomain.aspx when i create a subdomain "somename" then it should check if the subdomain already exists else it should create a directory called "somename" and should create a subdomain http://somename.somsite.com ans should map the directory "somename" to that subdomain.
any help wud be appreciated.

Thanks.