I don't know how easy it would be to dump the windows registry or the Lync settings or even sniff the network traffic to deduce which servers are being connected, but there are some nice articles on configuring Lync for Mac:
Specifically, it has the following advice to sign in to Lync for Mac 2011 with your Office 365 account:
- In the Microsoft Lync for Mac sign-in window, type your Office 365 email address, Microsoft Online Services ID, for example, email@example.com, and password.
- Click Advanced.
- Under Authentication, clear the Use Kerberos check box.
- Under Connection Settings, click Manual configuration.
- In both the Internal Server Name box and the External Server Name box, type sipdir.online.lync.com:443.
- Click OK.
- Click Sign In.
If that doesn't help, you might need to go fully into the managed preferences and get the values from your IT group on how they set things up and muck in the registry emulation database that Lync maintains in ether of these files:
Both of the above links come from the overall guide to Lync on Mac