OK to add clarification after the comments posted and the fact I realise my original question was massively confusing. This is what I am trying to achieve....
This
please see this page
http://msdn.microsoft.com/en-us/library/58wxa9w5(v=vs.100).aspx
Most importantly this line
Use when you are working with an existing project or your site targets an older version of IIS, such as IIS 6, and it is not very important that your testing environment match the production environment closely. This server option is the default in Visual Studio. However, the Visual Studio Development Server runs in a different security context than full IIS, and may fail to reveal errors that can occur when you deploy to a production version of IIS.
The issue is that IISExpress and the local dev server run under your security context. This allows them much more freedom to start processes and have access to files on the local system.
IIS however runs in a much stricter security context and has a limited access to the machine at hand. Imagine if IIS could do what you are proposing above. you could basically run any arbitrary code on the webserver.