Register a connection between a cell range and the data it uses
[C++]
int AddConnection(
   LPCSTR pszTopic
);
The topic string. Whenever this topic string is passed to the method UpdateCells this cell will be updated (as will any other cell connected to the topic).
The function returns a member of the enumeration CXllPush::AddConnectionReturnValues.
            A negative value indicates an error.
This function may only be called from the main thread.
			It is generally only called from add-in functions.
Header: xlppush.h
CXllPushApp Class 
					  | CXllPushApp Methods			 
					  | CXllPushApp::AddFunction()			 
					  | Steps to create an asynchronous add-in