Open your project and go to the projects Properties. In web apps, you should see a Web tab/choice. Click that, then you can configure which/what server you want to start. I think that the default is that VStudio likes to use it's internal IIS Express, but you can configure it to use IIS locally on the box or to use a custom server.
You can actually set the project to not start anything in the Start Action section on that 'tab' as well, and to simply wait until it registers a connection.
Note that if you are trying to debug using a non-local server, then remote debugging will have to be on on the server, which isn't a great idea in production environments.