This dialog will pop up if you click on "Configure":
With the help of this dialog you can define a key / joystick button for every button on the CD32 joypad. All possible key / joystick definitons are listed in the combo box. Select the one you want to use for the joypad button displayed in the title bar and click on the "Next Button" gadget. After you've configured all joypad buttons, your settings are applied to the current joypad configuration. If you click "Cancel" at any time nothing will be applied.