Thanks for your reply and help as always! I sorta adapted your code into the following inlined into the macroAction function (somehow I don’t like to clutter the individual macros into separate functions):
    case MACRO_ZOOM_IN:
        if (keyToggledOn(keyState))
        {
            handleKeyswitchEvent(Key_LeftControl, Macros.row, Macros.col, keyState);
            handleKeyswitchEvent(Key_mouseScrollUp, Macros.row, Macros.col, keyState);
        }
        break;
    case MACRO_ZOOM_OUT:
        if (keyToggledOn(keyState))
        {
            handleKeyswitchEvent(Key_LeftControl, Macros.row, Macros.col, keyState);
            handleKeyswitchEvent(Key_mouseScrollDn, Macros.row, Macros.col, keyState);
        }
        break;