My question involves a power of attorney in the state of: Indiana

My father-in-law has Alzheimers, with alot of other problems. We recently found out that his girlfriend (who is 74 and he is 72) has complete power of attorney on him and my husband is listed as second attorney in fact. She wants to put him in a nursing house and we dont want that to happen and she said we have no choice. We just recently saw the power of attorney but have no copy of it, supposedly it was done back in 2007. It was never recorded at the Recorder's office in the court house. How do we get a copy of it and is there any way the POA can be revoked, so we can keep him out of the nursing home, which he has always been against being put in one and she knows that......Can we do any thing about it? Thanks so much......