If I needed a moveable starfield, I generate a series of different component layers in Paint Shop Pro, using a combination of hsb noise and the Constellation plug in from Alien Skin (Xenofex II).  Then I make each layer transparent.  Now I go to Carrara and crate a series of simple very thin rectangular boxes.  Usually making them .05" along either the X or Y Axis.  By randomly arranging these, then creating a shader for each one using a different one of the starfield BMP files I generated in PSP.  Now your camera can move through the starfield and the stars will appear to move in relation to the camera and/or any models you use.  Make sure to rotate the rectangular panels randomly along each axis.