How can I tell who has a file open on a server?

I need a utility that will report who / what workstation has a file open (or locked) on a Windows 2000 Server. I have found a few utilities (ofl.exe, psfiles.exe) that will tell me the user or users that have files open, but I also need to know what workstation that user is connecting from. I have several users that logon to multiple workstations, so just the user name is not enough. . . Any suggestions.