The MONERRSTRUCT structure contains information about the current DDE error. A DDE monitoring application can use this structure to monitor errors returned by DDE Management Library functions.
typedef struct tagMONERRSTRUCT { // mest
UINT cb;
UINT wLastError;
DWORD dwTime;
HANDLE hTask;
} MONERRSTRUCT;
MONCBSTRUCT, MONCONVSTRUCT, MONHSZSTRUCT, MONLINKSTRUCT, MONMSGSTRUCT