How would i make an object rendering move in a cirlcle(?)

Use spherical coordinates.

You can convert Spherical coordinates to Cartesian by calculating:

x = radius * sin(phi) * cos(tetha)

y = radius * sin(phi) * sin(tetha)

z = radius * cos(phi)

So you can use a function like this:

Vector3 getPositionInSphere(Vector3 sphere_center, float radius, float theta, float phi)
{
    return Vector3(sphere_center.x + radius * sin(tetha) * cos(phi), 
                   sphere_center.y + radius * sin(tetha) * sin(phi), 
                   sphere_center.z + radius * cos(tetha)
}

Follow this image. p is the radius, ? (theta) azimuthal angle, and ? (phi) polar angle.
The angles are in radians.

So if you want the object to move in a circle on the xy-plane:
Set the ? to ?/2 (pi/2) and update ? each frame:

void Object::UpdateObject(float dt)
{
    angle += dt*PI/4; //rotate 45 degrees per seconds

    if(angle > 2*PI)
       angle -= 2*PI;

    ObjectPos = getPositionInSphere(sphere_center, radius, angle ,PI/2);
    D3DXMatrixTranslation(&matTrans, ObjectPos.x, ObjectPos.y, ObjectPos.z);

    [...]
}

EDIT #1:

BTW, you might have to switch the coordinates in the function getPositionInSphere if you're using a different coordinate system.

For the typical D3D left-hand coordinate system:

Vector3 getPositionInSphereD3D(Vector3 sphere_center, float radius, float theta, float phi)
{
    return Vector3(sphere_center.x + radius * sin(phi) * sin(theta),
                   sphere_center.y + radius * cos(phi),
                   sphere_center.z + radius * sin(phi) * cos(theta));
}

EDIT #2:

Since you only want to move in a circle (phi is constant PI/2), the function turns into polar coordinates:

Vector3 getPositionInCircleD3D(Vector3 sphere_center, float radius, float theta)
{
    return Vector3(sphere_center.x + radius * sin(theta),
                   sphere_center.y,
                   sphere_center.z + radius * cos(theta));
}

You're resetting the angle to 0 every update, that's why it doesn't change. Move angle to the class definition and only initialize it to 0 in the constructor.

class Lazer
{
    [...]
    float angle;
};

Laser::Laser() : angle(0.0f)
{
    [...]
}

void Lazer::UpdateLazer(float dt)
{
    angle += dt*D3DX_PI / 4; //rotate 45 degrees per seconds

    [...]
}

Use the modified function I wrote on reply #4 getPositionInSphereD3D.