Yes you can, as Orpheum pointed out, a access point is basically a gateway to your wired network or vise versa.
In you case, you probably need to set up another conventional nic to your 2000 server and link it up to your wired lan to serve as a gateway between the two.
You don't need additional software, in terms of the routing and connectivity, as this would be just conventional routing configuration. However security is another matter. Most AP box comes out of the box with security, such as encryptions, authentication, etc. It is possible to produce similar or better security with. Additional point you might want to consider is that a standard wireless NIC, have a very short range. Most ppl uses AP box, cause by default it generates a stronger signal.