Create GUI for plotting serial string data

Hi, im developing a system control to display some sensors with a PSoC and then send that data (strings) into Matlab by the serial port. I've succeded plotting them in the workspace, but now im trying to develop a GUI in order to display these sensor graphs. the matlab´s code is the shown below:

clear all;
close all;
clc;

%Inicialización del puertos
paco=0
PS=serial('COM2');

set(PS,'Baudrate',300); % se configura la velocidad a 300

set(PS,'StopBits',1); % se configura bit de parada a uno

set(PS,'DataBits',8); % se configura que el dato es de 8 bits,     debe estar entre 5 y 8
set(PS,'Parity','none'); % se configura sin paridad

set(PS,'Terminator','CR/LF');% “c” caracter con que finaliza el envío. \r\n

set(PS,'OutputBufferSize',512); % ”n” es el número de bytes a enviar

set(PS,'InputBufferSize' ,512); % ”n” es el número de bytes a recibir

set(PS,'Timeout',5); % 5 segundos de tiempo de espera

interrruptores='interruptores';
fopen(PS);

%iniciañización de las variables
K1=[]; K2=[]; K3=[]; K4=[]; K5=[];
encendido=1;

while (encendido==1)

   Instruccion=fscanf(PS,'%s');
    Dato=fscanf(PS,'%s');

        switch(Instruccion)
          case 'FSR' 
                K1=[K1 str2num(Dato)*0.01953125]

           case 'AX' 
                K2=[K2 str2num(Dato)*0.01953125]

            case 'AY'
                K3=[K3 str2num(Dato)*0.01953125]

             case 'HALL'
                K4=[K4 str2num(Dato)]

              case 'Fin'
                paco=1;% Mensaje que le hace salir del bucle

        otherwise
                K5=[K5 str2num(Dato)]
    end

     figure(1)
     hold off;
     plot(K1,'g')
     hold on;
     plot(K2,'r')
     hold on;
     plot(K3,'b')
     hold on;
     plot(K4,'y')

end;
%Cerrado bueno
fclo  se(PS);
delete(PS);
clear PS;
INSTRFIND

The GUI I want to do just contains one axes and a start button and i just would like to know where to use this code, can anybody help me?? Thanks in advance