Q:

multiple domains same folder using url rewrites how does that affect cookies and ssl certs? 

I have a folder that is hosting a web application.  Our clients are wanting to direct their website our 'web portal' so their customers can view their account information. 
In my first attempts I have the following:
domain:  test.domain1.com --> c:\websites\testsite
I added a second and tried to point to the same folder:
domain:  test.anotherdomain.com --> c:\websites\testsite
Each sub domain has it's own ssl certificated. 
This didn't work.  I kept getting a 404 error on the test.anotherdomain.com.  I researched it a little and found this post:
IIS 7 - Multiple IIS Sites pointed at same directory.  How is this accomplished? 
So, I looked up url rewrites and found this post:
Using IIS 7.5 URL Rewrite, how can I redirect all requests not from a particular subdomain to a specific page? 
I have three questions:

How do I redirect the test.anotherdomain.com to the first domain's folder and still retain the url so it looks like the test.anotherdomain.com?  This is important so they customers think it is still within our client's website. 
How will this affect the certificates if at all? 
How will this affect the cookies if at all? 

I'm at a loss since this isn't my area of expertise. 
Thank you very much for your help. 

A:

I didn't need to redirect.  I was overthinking it.  I was just able to add the new domain to the  bindings and it worked just the same.  The new url worked fine from the same directory...

