How to debug ASP site without port number on VS 2012 Express

How to debug ASP site without port number on VS 2012 Express

I'm trying to debug an ASP.NET 4.0 web site using Visual Studio Express
2012. I've configured the project settings to use the local IIS web server
which was installed with VS. I need to use IIS so that urlrewritingnet
will work.
I need to run the site locally without a port number. Currently it runs as
http://localhost:4652/ which breaks some of the routines since they
reference Request.Url.Host. This results in attempts to access resources
using http://localhost/.
There is a lot of code to this site and it would be extremely easier and
quicker (I think) to just configure my local debug to run on localhost
instead of localhost:4652. Is there a way of doing this?
Since it's IIS Express installed with VS there is no configuration manager
for IIS. When I click PROJECT -> mysite Properties and change the Project
Url (under Use Local IIS Web Server) to http://localhost/ I get a warning
that reads:
The local IIS Express URL http://localhost/ specified for Web project
mysite has not been configured. To keep these settings you need to
configure the virtual directory. Would you like to create the virtual
directory now?
When I click on Yes, I get another dialog box saying:
Unable to create the virtual directory http://localhost/
Does anyone know if this should or should not work and if it can work, how
do I do it?