IP Logs

I am trying to track back the machine that was using an IP address in our local area network from about 3 weeks ago.
I have the IP, a time, and a date, but I really need to know the machine that was using that IP address at that time.
I am on a 2000 network with a DHCP server configured for their local IP range. Are there any logs or any way to determine the machine or user login that used that IP at that time?