single analog pin to control multiple (SVG buttons)

Hi all. I am using a single analog pin to control multiple buttons.

How can I repeat this scheme using GVS button?
http://static12.insales.ru/images/products/1/8155/27508699/troyka-button.2.jpg

Here is the arduino code:

#define ERROR_WINDOW 50 // +/- this value
#define BUTTONDELAY 20
#define DEBUG_ON

int analogPin = 3; // switch circuit input connected to analog pin 3
long buttonLastChecked = 0; // variable to limit the button getting checked every cycle

void setup () {
Serial.begin(9600);
pinMode(A3, INPUT);
}

void loop()
{
if( buttonLastChecked == 0 ) // see if this is the first time checking the buttons
buttonLastChecked = millis()+BUTTONDELAY; // force a check this cycle
if( millis() - buttonLastChecked > BUTTONDELAY ) { // make sure a reasonable delay passed
if( int buttNum = buttonPushed(analogPin) ) {
Serial.print("Button "); Serial.print(buttNum); Serial.println(" was pushed.");
}
buttonLastChecked = millis(); // reset the lastChecked value
}
}

int buttonPushed(int pinNum) {
int val = 0; // variable to store the read value
digitalWrite((14+pinNum), HIGH); // enable the 20k internal pullup
val = analogRead(pinNum); // read the input pin

// we don't use the upper position because that is the same as the
// all-open switch value when the internal 20K ohm pullup is enabled.
//if( val >= 923 and val <= 1023 )
// Serial.println("switch 0 pressed/triggered");
if( val >= 475 and val <= 890 ) { // 830
#ifdef DEBUG_ON
Serial.println("switch 1 pressed/triggered");
#endif
return 1;
}
else if ( val >= (375-ERROR_WINDOW) and val <= (375+ERROR_WINDOW) ) { // 693
#ifdef DEBUG_ON
Serial.println("switch 2 pressed/triggered");
#endif
return 2;
}
else if ( val >= (275-ERROR_WINDOW) and val <= (275+ERROR_WINDOW) ) { // 430
#ifdef DEBUG_ON
Serial.println("switch 3 pressed/triggered");
#endif
return 3;
}
else if ( val >= (175-ERROR_WINDOW) and val <= (175+ERROR_WINDOW) ) { // 230
#ifdef DEBUG_ON
Serial.println("switch 4 pressed/triggered");
#endif
return 4;
}

else
return 0; // no button found to have been pushed
}

Thanks in advance!

http://static12.insales.ru/images/products/1/8155/27508699/troyka-button.2.jpg

This looks like a SPST switch. Read it digital.

Bypass everything on the board, except the closing contact, then use it like any other button in your anlaog button chain.

Most probably the contact will be accessible between S (Signal?) and either G (Gnd?) or V (Vcc?).