Mel Animation Joints Randomly

//Random Rotate
float $speed = 1;

joint226|joint3.rotateY = (300 / 50) * rand (sin(frame * (1/ $speed)) + 1);
joint226|joint3.rotateX = (300 / 50) * rand (sin(frame * (1/ $speed)) + 1);

joint226|joint3.rotateZ = (300 / 50) * rand (sin(frame * (1/ $speed)) + 1);

//END Here