A converter would give you a call to the exact same method VB uses:
Interaction.CreateObject("Microsoft.XMLHTTP")
You could instead use non-VB-specific classes.
Activator.CreateInstance(Type.GetTypeFromProgID("Microsoft.XMLHTTP"))
Or you could find an equivalent class to do the same work. For example HttpWebRequest.
http://msdn.microsoft.com/en-us/magazine/cc301587.aspx