Use the ICIServer Interface Sites method to access the list of Sites and open the ICISites interface. You can subsequently use the ICISites Item method to retrieve a pointer to a particular Site. This method returns a pointer to an ICISites interface.
HRESULT Sites([out, retval] ICISites** prop);
Example in VB:
Dim Server As CIServer 'assumes the SFTPCOMInterface Type Library is referenced by the VB IDE
Dim Site As CISite 'instantiates the ISite interface
Dim Sites As CISites 'instantiates the ISites interface
'insert connection routines here
'now retrieve the list of sites and then set a pointer to the first one
Set Sites = Server.Sites 'now retrieve the list of sites in the server
Set Site = Sites.Item(0)
'continue rest of code...