atlcomcli.h header file not found.

Using Visual Studio Express 2012 I'm creating a C++ project.  I need to use CComvariant for one line in my code!  I understand that CComvariant requires;

#include <atlcomcli.h>

however intellisense tells me that this header file is not found.  Please can someone tell me how I may use CComvariant in Visual Studio Express?

Thanks,

Riskybiz.