How to create host name top level site with stsadm

For example, if you have a Web application named http://sharepoint.com and you want to add a host-named site collection with the URL http://about.sharepoint.com, use the following command:

stsadm.exe -o createsite -url http://about.sharepoint.com -ownerlogin domain\siteowner -owneremail siteowner@sharepoint.com -hhurl http://sharepoint.com

Renaming Site
stsadm -o renamesite -oldUrl http://www.name.com -newUrl http://www.newname.com