This command allows you to communicate with an external program via Microsoft Windows Dynamic Data Exchange (DDE). You must consult the documentation of your external program to determine the syntax of its macros, and its defined topic names. The server name is usually the name of the program itself (without the .EXE). There are also built-in functions for DDE:
If you open a DDE connection with the %ddeopen(server,topic) function, then you do not need to specify the server and topic in the other functions. This DDE connection is global to zMUD and available in any window. When you are finished with a DDE connection, use the %ddeclose() function.
Note the zMUD also acts as its own DDE server. The server name is zmud, the topic name is also zmud, and the only defined item name is data. Using a DDEPoke you can set data to any command string and cause all variables and function calls to be expanded. You can then use a DDE call to retrieve the resulting value of data. Using DDEMacro you can send a command string to zMUD and cause it to be executed as if it were typed.
Since DDE is somewhat obscure, I have included a bunch of useful examples: