connect GUI (create from guide editor) with class in package

Hello I have question. How connect gui (its create from guide editor) with class? I have gui_interface.fig , gui_interface.m (callbacks), and gui.m (class) I have idea that idea that class is controller to gui_interface, but i have probleme how connecting this two .m file. I try import gui_interface.m like mehods to gui.m but that communicate only gui.m with gui_interface.m and only one main function (function gui_interface()) but i need change data between both file. Second option is use:

    properties (Access = private)      
        gui_h;
    end
    methods
        function obj = gui()
            obj.gui_h = guihandles(gui_interface);  
  end

but this works only if when its isnt in package. If there is package there is error

??? Error using ==> load Unable to read file C:\Users\Balrock\Desktop\Škola\PNK\ekg\gui_interface.fig: No such file or directory. Have you some idea how connect it? Thx a lot and sorry for my bad english