Use name as subdomain in url

I am using kentico 9 solution where i have one url like below: localhost/Home.aspx Now i have to add one name like subdomain.Below is the example: localhost/vikash/Home.aspx If I try to use this URL it is redirecting me to error page. But here I want it to accept any name here.Or in settings> Url@Seo >DefaultUrlPathPrefix: in this section if i add any name it is working fine. can we make this field configurable, That can accept any string value there.Can i have any idea regarding this?