arduino vs gamepad vs "software"

hello, i was trying to build pan and tilt robot with usb game pad controller. usb is connected to pc and there will be a "software" that is going to receive inputs from the joystick and send command to the arduino. help me how to do it

You could use a Leonardo or Micro or Teensy 2 to read the game controller and act as an HID (human interface device) to the PC. HID is the standard for USB joysticks, mice and keyboards (any or all at once) that work with almost every PC as-is.