The Macro Properties screen appears when you select the Record Macroitem in the Macros menu, and when you click the Properties button when organizing macros.
EditPad Pro macros have only two properties: a name, and an optional keyboard shortcut. Each macro must have a unique name. If you start recording a new macro with the same name as an existing macro, the existing macro is automatically and silently replaced.
The keyboard shortcut can either be a single key combination, or a double key combination. Assigning a shortcut to a macro works just like assigning shortcuts in the Keyboard preferences. The procedure is explained in detail in the help topic about Keyboard preferences. If you assign a shortcut to a macro that is already assigned to another macro, the new macro will take over the shortcut from the old macro. You cannot assign a shortcut that's already used for a menu item to a macro.