What do you mean by hand gesture? What type of sensor are you planning to use, flex sensor, accelerometer etc.? In which part of the program you're having doubt?
The basic principle will be same, for analog sensors you've to use an ADC and execute the movements accordingly. For robotic vehicles you can use either a DC Motor or Stepper Motor and for angular movements you can use a servo motor.
I'm not aware of AVR Studio, but if you are using an analog Accelerometer there will be three pins (for each axis, X, Y and Z). And according to the tilt, the output voltage of each pins varies. So what you have to do is to configure three ADC channels in your micro-controller and drive the motor (using a motor driver) which can be either a stepper or a low rpm DC Motor.