The sample can be fixed and will start working as expected once the following changes are made. 1. Open DDEHandlerVB.vbp project2. DDEHandler class 3. Locate the following function Private Function IDDECommandHandler_CanExecute(ByVal Command As String) As Boolean4. Locate the following line in the CanExecute function and comment it out. Command = StrConv(Command, vbUnicode)5. Locate the folllowing function Private Sub IDDECommandHandler_Execute(ByVal Command As String)6. Locate the following line in the Execute function and comment it out. Command = StrConv(Command, vbUnicode)7. Compile and register the dll8. Make the test in ArcMap and the sample should work.