I believe you can use the ellipsoid function for this. Example:
[x,y,z] = ellipsoid(0,-0.5,0,6,3.25,3.25);
will create an ellipsoid with centre at (0,-0.5,0) and has semi -axis length (6,3.25,3.25). Now, coming to the points on the surface:
You can utilize the x,y and z variables returned by the function. Basically,
is a point on the ellipsoid. The 21 faces restriction can be made finer by using an extra argument for "number of faces". I hope this helps!