Right now, I do the following manual steps to run an ASP.NET website on my PC:
From the visual studio command line you could do the following:
devenv "C:\path\FooSolution.sln" /run
MSDN Devenv Command Line Switches Reference
Wrapping this all up into a batch file (assuming VS 2012) it would become:
call "C:\Program Files\Microsoft Visual Studio 11.0\Common7\Tools\VsDevCmd.bat"
devenv "C:\path\FooSolution.sln" /Run
Update
To run this outside of Visual Studio with IIS Express you would use the following commands:
msbuild.exe "C:\path\FooSolution.sln"
iisexpress /path:c:\path\fooapp\ /port:666
start "" http://localhost:666
Please note there are many configuration options for both msbuild and iisexpress command. You will need to tailor them to suite your needs.
Running IIS Express from the Command Line