There are two classes of DDE functions in Cicode, the original DDE functions and the later DDEh functions.
The original Cicode DDE functions do not return a DDE Channel Number and were designed to insulate the user from the need to manage DDE Channels. The DDERead(), DDEPost(), DDEWrite(), and DDEExec() functions each perform a single exchange of data. Each of these functions starts a DDE conversation with the external application, sends or receives the data (or command), and ends the conversation - in one operation.
The Cicode DDEhfunctions were introduced to afford more control over DDE communications, especially for Network DDE and for circumstances where it is necessary to explicitly terminate and re-initiate a DDE Channel (after deleting rows from a table for example).
The DDE handle (DDEh...)functions return a handle to the conversation - a DDE channel number.
Use the DDEh handle functions for Network DDE, and for Access DDE.