Hi, although you said that you received info from the Red Cross, did you also check with the archive at Auschwitz-Birkenau? You can do a search for prisoners at their website:
http://en.auschwitz.org/m/index.php?option=com_wrapper&I...Przednowek surname is found in their database, one of them Moric Przednowek was born in Chmielnik on 23 May 1900 - Brussel is also included with the name. Perhaps this is a relative? I've attached an image for you to see.
I made a request to the Auschwitz-Birkenau archives for some of my family and received a reply within a few weeks.
There are several villages named Chmielnik - you can see several listed here:
http://en.wikipedia.org/wiki/Chmielnik_(disambiguation)
The Przednowek surname that I'm familiar with is from the Subcarpathian - Podkarpackie Voivodeship....near Rzeszow. There is a Chmielnik village nearby. I don't know anything about the village, so I can not comment on whether Przednowek surname can be found there. The Przednowek's that I'm familiar with are Roman Catholic and Greek Catholic.
I hope this helps a little.