Hi, there are essentially 4 approaches:

1. Contact the trustee and ask them for the bank contact info. Be really sweet and you might have some luck. But don't be surprised if they say no.
2. Start persistently researching phone numbers and calling into the bank until you get to the right department and ultimately the right person.
3. Use the Lane Guide to find the right starting point at the bank - they do most of the research in #2 for you.
4. Wait until the property is listed as an REO in the MLS or with an auction company.

Hope that helps.