<oTopBar>:getAccel(<nInkeyValue>) --> nPosition

        <nInkeyValue> is a numeric value that indicates the inkey value to be
        checked.

        Returns a numeric value that indicates the position in the top bar
        menu of the first item whose accelerator key matches that which is
        specified by <nInkeyValue>.  The accelerator key is defined using the
        & character in MenuItem:caption.

        getAccel() is a method of the TopBarMenu class that is used for
        determining whether a key press should be interpreted as a user
        request to evoke the data variable of a particular top bar menu item.