Hello, I'm doing a proyect with WebGL and Three.js (Newbie here)

I'm looking for how to positioning the 3D Object in the center of the target. 

So far, I have a Cube which appers on screen, but I can't make it to stay on the marker, also some camera problems..

I have looked at this and I take the Matrix Pose from there:

https://developer.vuforia.com/forum/faq/technical-how-do-i-get-camera-position

This is my code:

                var VIEW_ANGLE = 45,

                ASPECT = WIDTH / HEIGHT,

                NEAR = 0.1,

                FAR = 10000;

                var renderer = new THREE.WebGLRenderer();

                var camera = new THREE.PerspectiveCamera(VIEW_ANGLE, ASPECT, NEAR, FAR);

                var scene = new THREE.Scene();

                    cam_x = invTranspMV.data[12];

                    cam_y = invTranspMV.data[13];

                    cam_z = invTranspMV.data[14];

                    cam_right_x = invTranspMV.data[0];

                    cam_right_y = invTranspMV.data[1];

                    cam_right_z = invTranspMV.data[2];

                    cam_up_x    = -invTranspMV.data[4];

                    cam_up_y    = -invTranspMV.data[5];

                    cam_up_z    = -invTranspMV.data[6];

                    cam_dir_x   = invTranspMV.data[8];

                    cam_dir_y   = invTranspMV.data[9];

                    cam_dir_z   = invTranspMV.data[10];

                    //Print the cube..

                    three.cube.position.x= cam_x * -1;

                    three.cube.position.y= cam_y * -1;

                    three.cube.position.z= cam_z * -1;

                    three.cube.rotation.x = cam_right_y*-1;

                    three.cube.rotation.y = cam_up_y*-1;

                    three.cube.rotation.z = cam_up_z*-1;

                    // < -- Set the Camera -- >

                    three.camera.position.x = Math.sin(cam_up_y) * 600; // cRX

                    three.camera.position.y = 0;

                    three.camera.position.z = Math.cos(cam_right_y) * 600; //CRZ cDX cDY

                    three.camera.rotation.x = 0;

                    three.camera.rotation.y = 0;

                    three.camera.rotation.z = 0;

                    three.camera.lookAt(three.scene.position);

                    three.renderer.render(three.scene, three.camera);

So help will be so much appreaciated, also notice I'm new at this.

Thank you in advance...