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This probably isn't the best place to look. Very few people who are actually Polish feel the need to discuss their own country in a foreign language, especially since there are a thousand online places to do so in their own.
Why not have a look on Facebook to see if there are people with that name in that place? You can use a filter in the search function to do that. Also, even Google is worth a look. I put kosiorek Siedlce into the search function and quite a few results came up, including contact details. If you have a cut and paste message to send to each one, it will be quick and easy and you may well get a positive reply from one or more.
Someone there may well be delighted to hear from you.