Including File Selector Dialog Box in Abaqus GUI

I'm working on an Abaqus GUI where the main dialog box needs to bring up a file selector dialog box.  When the user finishes selecting files and closes the box, the main dialog will add the selected file names to a table on the main dialog box.  I can get the AFXFileSelectorDialog to open and allow files to be selected, and I tried to use FXMAPFUNC to capture a SEL_COMMAND message from the file selector; but the mapped function never gets called.

Does someone have a plug-in that they could share that uses a secondary file selection box similar to this?  It would help me to have a working example that I could follow.  Or, is there a way to monitor the messages so I could debug why my mapped function is not working?