Subdomain on my asp.net mvc 3.5 site

Hello.
I have made a simple private asp.net mvc site.
Now I want to make a subdomain where I can run a workhours application that I have dabbled with.

I've tried this KB.
It doesn't tell me exactely which file that I should put the code? I suspect it is in the an index.aspx or default.aspx? Well, I tried this, and it didnt work. Guess the issue is that asp.net mvc uses Global.asax?
Will the code work in the Global.asax?

I have set the dns for the subdomain to the same ip as the root domain, and made a folder with the same name as the subdomain.

Anyone can help me here?