you need to derive a class from wxDDEConnection and another from wxDDEClient.
The custom wxDDEConnection class will intercept communications in
a `conversation' with a server, and the custom wxDDEServer is required
-so that a user-overriden \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} member can return
+so that a user-overridden \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} member can return
a wxDDEConnection of the required class, when a connection is made.
This DDE-based implementation is