I'm sure there are some law firms that handle that sort of thing.
The best way to value it would be to find similar names and how much they sold for recently.
Most likely, the domain has little value to anyone except the company that wants it. So it will just be a matter of how bad they want it.
Additionally, depending on the name, it could be that the corporation can take it for nothing as they own the trademark.
Especially if the domain is not already being used legitimately for an existing business or other purpose.
Check out nissan.com to read about that long drawn out saga.