This is how I made ball movement. It was mostly taken from the example (although I had to work most of it out myself):

Code:

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var force[3];
function movement_forces(body) 
{
	var bodyMass;
	bodyMass = NewtonGetBodyMass(body);
	NewtonBodyAddForce(body, 0, 0, bodyMass * (newtonGravity + force.z));
	NewtonBodyAddTorque(body, bodyMass * my.move_vec_x, bodyMass * my.move_vec_y, bodyMass * my.move_vec_z);
}
////////////////////////////////////////////////////////////
// Player Initialization
////////////////////////////////////////////////////////////
define move_vec_x, skill98;
define move_vec_y, skill99;
define move_vec_z, skill100;
action initialize_player
{
	player = my;

	var body;
	my.collision_sph_box = on; // sphere?
	my.mass = 10;
	my.linear_drag = 0.1;
	my.angular_drag_x = 0.1;
	my.angular_drag_y = 0.1;
	my.angular_drag_z = 0.1;
	my.start_active = on;
	my.shape_factor = 0.9; // density
	NewtonCreateGravityEntity(ivory_material);
	dll_handle = newtonHandle;

	body = NewtonGetBody(my);
	NewtonSetBodyAutoActiveState(body, 0);
	NewtonSetBodyActiveState(body, 1);
	// asign a special force event to the rover
	NewtonSetBodyForceAndTorque(body, movement_forces);

	while(1)
	{
		vec_set(my.move_vec_x, nullvector);
		vec_set(force, nullvector);
		my.move_vec_x = key_cur - key_cul;
		my.move_vec_y = key_cuu - key_cud;
		if(key_space)
		{
			force.z = 1000;
		}
		//vec_rotate(my.move_vec_x, vector(camera.pan, 0, 0));
		vec_normalize(my.move_vec_x, 100);
		wait(1);
	}
}

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