You can find a complete example in the following Functional Developer installation folder:
Examples\duim-ole\ocx-scribble\
See its README.html file for a discussion.
Functional Developer does not include a control container for testing this example, but if you have Microsoft Visual C++ there is a Test Container application you can use.
You can also embed the control in a compound document container, such as WordPad, but its properties will not be accessible. To do this, first build the control in the Functional Developer IDE, then register the control with regsvr32 ocx-scribble.dll at an MS-DOS prompt, and then use Insert > Object and choose DUIM OCX Scribble from the Object Type list.