How to override the IIS virtual directory in an MSI install

Question

I created an MSI to install a WCF web service. It's running fine, but when I run the MSI, it defaults to install as MyCompany.RCT.WCFWebServicesSetup instead of MyCompany.RCT.WCFWebServices.

1) I would prefer to force the name of the virtual directory, and not even let the user change it, or

2) I would at least like to provide the "correct" name (different from the Visual Studio project name) [i.e. without the word Setup on the end].

Thanks,

Neal