Sigma make (or made) a 28mm f/1.8 EX DG Macro lens, if that's what you're asking about.
If so, then this won't give autofocus on a D5000. Many people use manual focus for macro work anyway, so it might not be a problem. I believe the D5000 has Live View, which simplifies things somewhat
The Sigma lens has a maximum reproduction ratio of 1:2.9 - i.e. you could fill the frame with an object about 2.9 inches across. If your kit lens is one of the 18-55mm DX Nikkors then its maximum reproduction ratio is 1:3.2 so it's not that far behind.
A supplementary close-up lens may be another, equally inexpensive, option.