I had a power of attorney for my dad but I lost the paperwork. Suggestions?

Why would the old one be in public records? Did you record it with the county court? If it was prepared by a lawyer, see if the lawyer kept a copy. Otherwise there really wouldn’t be a public record.

In my State you don't file POAs. Wish they did. The only thing you can do is find the Lawyer who drew it up and get a copy. If the person who assigned you now has a Dementia, you will not be able to have another drawn up.

Contact the lawyer who created the document.

Does your dad still have his copy? Would any other family members have been given a copy?

Most banks will require an original signed document. You might want to start by contacting the original lawyer who wrote up the POA. They should have it on file and can make a notarized "copy" that should have the same power as the one that was misplaced.

Chances are that a probate court is not an option. In most cases there would be no need for that.

But, you can record anything with the county clerk. If you get a new one, many states have options for virtual notaries when it comes time to sign. Check with the attorney that prepared the POA. That office would be able to supply you with a certified copy, which you will need.

if he cant consent for himself anymore, file for conservatorship in your county.

I know it is too late to help you but it might help others. I have scanned and saved all the documents (advanced directive, medical power of attorney, POA, and will) onto a flash drive. I know it isn't the same as having the originals but most places asking for any of those documents (except the will) usually need them loaded onto a website or just a copy for their records.
If you have ever used the POA and had to provide a copy, you might see if they still have a copy in his records.
And I suggest everyone purchase a firebox and keep copies or originals of documents (including birth certificates) in there. Because I guarantee sooner or later, someone is going to ask for them.

You may have filed a copy with his physician.

If you know the POA was recorded in NY, it is probably easier to obtain a copy from the records division of the NY county in which it was recorded it. Might be worth the extra fee to order a certified copy just to be safe, even though a copy of the recorded doc should be honored by any 3rd party. Most states do not require a general durable POA to be recorded (unless it involves a real estate transaction), so it may not have been recorded in NY.