If your application currently supports DDE Execute commands and your OLE server application supports the StdExecute protocol, the application will receive DDE Execute strings not only through DDE messages but also through the Execute callback functions (in the OLESERVER and OLESERVERDOC VTBLs) when those commands are passed through OLESVR.DLL. If your application has existing code that parses an Execute string, isolate it so that it is callable from your WM_DDE_EXECUTE case or from either Execute callback. The application may also have code to execute the commands after parsing, which you can also isolate to be callable from these separate locations.