Syntax
STSADM.EXE -o createsite -url <url-to-site-collection> -ownerlogin domain\user -owneremail <email-address>

Example
STSADM.EXE -o createsite -url http://servername:9009/sites/EmptySiteCollectionName -ownerlogin mydomain\praveen -owneremail abc@xyz.com