Need help in ASP.Net wildcard Subdomain Configuration on Plesk

I have created a website lets say example.com, now I have a feature that on click of link it should be moved to nav.example.com.
Now the subdomain name can be any name selected by user, so I can not create the subdomain,
So I google and found that wildcard DNS entry with “A” can give access to the account. With this change I am able to ping the subdomain successfully, and also I am able to browse it but It always shows server default page.

I tried many things :
[http://www.dennisonpro.info/simple-multitenancy-with-asp-net-mvc-4/][1]
[http://stackoverflow.com/questions/278668/is-it-possible-to-make-an-asp-net-mvc-route-based-on-a-subdomain][2]
[https://www.digitalocean.com/community/tutorials/how-to-set-up-and-test-dns-subdomains-with-digitalocean-s-dns-panel][1]
I have also added UrlRewrite :
 <rewrite >
      <rules>
        <rule name="CName to URL"  stopProcessing="true">
          <match url=".*" />
          <conditions>
            <add input="{HTTP_HOST}"  pattern="^(?!www)(.*).ebaraati.com$" />
          </conditions>
          <action type="Rewrite" url="http://ebaraati.com/Preview/Index?url={C:1}" appendQueryString="false"  />
        </rule>
      </rules>
    </rewrite>


Any help would be appreciated ?



  [1]: http://www.dennisonpro.info/simple-multitenancy-with-asp-net-mvc-4/
  [2]: http://stackoverflow.com/questions/278668/is-it-possible-to-make-an-asp-net-mvc-route-based-on-a-subdomain

Requirement :
A user can create teams, and every team will have a subdomain associated to it.
Now user1 select a subdomain “teamA”. Now user wants to see team property, member mapping, it will be redirect to teamA.example.com

Now there can be n number of teams, so I can not create subdomain for every team, so I need to set up dynamic domain system.