If you want contact with Michal and Katarzyna Niemczyk family in Giedlarowa, send letter in English
[with explanation] to Library in Giedlarowa - probably somebody from Library will contact you
with your greatgrandfathers [= Jozef Niemczyk] relatives;

Biblioteka Publiczna Gminna
37-300 Giedlarowa 285
woj. podkarpackie
Poland

use also;

http://translate.google.com/#en/pl/

for translation your English letter to Polish and in future Polish to English.

Presently, a lot of young in Poland speaks English and I expect, that you will have a nice surprise.

Good luck in contact.