how to set transform/rotation origin of 3D object?

[cheetahxspeed]

I wish to rotate a 3D object, the rotation is based on the center point of the object. I wish to change it to the one edge of the object.
How should I do it?

Model {
            z: 10
            source: "#Cube"
            position: Qt.vector3d(500, 0, 0)
            scale: Qt.vector3d(10, 0.05, 0.05)
            eulerRotation: Qt.vector3d(xDegree.value, yDegree.value, zDegree.value)

            materials: DefaultMaterial {
                lighting: DefaultMaterial.NoLighting
                diffuseColor: "red"
            }
        }

Here is the rotation effect (it looks like a 2D line, as I scaled it)

Thank you very much for your help in advance!