Generally once an OST file becomes disconnected from a profile, the data
inside can't be salvaged. However you might give this a try if you still
have access to an Exchange server.
1) Create a new profile and configure it for offline storage
2) Connect to Exchange using that new profile
3) Get 1 good sync of folders/address book
4) Shutdown and disconnect network
5) Replace new OST with a copy of the OST file that contains data you need
6) Start Outlook
7) If Outlook starts with the salvaged OST, export contents to PST
8) Shutdown Outlook and undo changes above
The only other option I can think of if one doesn't have access to Exchange
and the OST file came from Outlook 97 thru 2002, is a tool called OST2PST.
Use your favorite search engine to find.