COM Port Interrupt in Multiwindow App

I was wondering if it is possible to pass an interrupt function between mutiwindow applications? I know that I can pass variables between apps, but could I also tell the main app to use the interrupt callback that was set in the child app?

The basic idea is as following. Two or more windows for the app. The first main window visualizes measurement results from an external board that sends messages through a COM port. The measurement results are taken automatically by the external board and transmitted as soon as a result becomes available. To keep the application clearly arranged the dialog for the selection of the used COM port should be located in another window.

This code already sets the COM Port information in the parent app when the COM port was connected.

Child:

properties (Access = private)
    CallingApp
end

function startupFcn(app,mainapp)
    app.CallingApp = mainapp;
    freeports = serialportlist("available");
    app.SelectCOMPortDropDown.Items = freeports;
end

function OKButtonPushed(app, event)
    port = getappdata(app.SelectedCOMPortDropDownLabels,'comport');
    s = serial(port,'BaudRate',9600);
    s.BytesAvailableFcnCount = 1;
    s.BytesAvailableFcn = @uartcallback;
    fopen(s);
        if(strcmpi(s.Status,'Open'))
            setcomport(app.Callingapp,s);
        end
    app.delete;
end

Parent:

methods(Access=public)
    function setcomport(app,port)
        app.comport = port;
        app.comopend = 1;
    end
end

but it does not seems that I can now simply use the uartcallback in the main window. Any idea how to make it work?

Best regards,

Chris