To execute a remote command, the client application posts to the server a WM_DDE_EXECUTE message containing a pointer to a shared-memory object that contains a DDESTRUCT data structure and a command string, as shown in the following code fragment:
WinDdePostMsg(hwndServer, /* Handle of server */ hwndClient, /* Handle of client */ WM_DDE_EXECUTE, /* Message */ pddeStruct, /* Shared-memory pointer */ DDEPM_RETRY); /* Retry */