query

hi,
I am trying to exchange data between simulink engine and m-gui.
In my gui ,is there any way to receive output from c s-function inside the model.
Also using level 2-matlab s-function also its not working..
fun below is a callback of pushbutton for simulation
******************************************
function simstart(s,e)
        set_param('modelname','SimulationCommand','start');
       
        h = add_exec_event_listener('modelname/Level-2 MATLAB S-Function', 'PostOutputs', @acallthis);
end

  function callthis(s,h)
        display('hiii');
        global d;
        d=10;
    end
*******************************************
Please help me....Thanx in advance.