First of all, you will need to find out which Paprotnia ( en.wikipedia.org/wiki/Paprotnia ) is the correct one. Once you know, check which parish was responsible, and then check at which state archive the relevant church books are now stored (provided they have survived the war and/ or weren't looted by the Soviets). Many records have been digitized lately with the help of EU funds, so you might be lucky to find what you're looking for online.
If you can't narrow it down, you will have to check a lot of church books, I'm afraid. Were your ancestors catholic or Jewish?