If you have to use a Win2000 box to do it from try using PWDUMP3. You can get it at http://www.ebiz-tech.com/index.htm. PWDUMP3 adds Windows 2000 functionality. However, if you can use an NT box and the envrioment that your auditing is a mixed NT/2000 architecture than L0phtCrack will still be able to sniff out password hashes for you.
Most admins can't set the NTLMv2 setting on there networks because of some legacy app or a CEO wanting Windows98 on thier box, so the hashes are backwards compatible...even on 2000 boxes. =)
Worse case, you can enumerate the userlist via a null session (net use \\x.x.x.x\ipc$), grab the user list and then run NAT against the domain utilizing a brute force technique
Good luck on your audit.