This is not an easy trace. I am a Danielewicz, which means son of Daniel. The Danielewiczs I know of are of the Jewish religion, though they were the ONLY Jewish family in the area of Lomza, Poland to have that name. It was very uncommon. The family is related to the Kafka family, the Wstega (vish-tenga) Family and the Chmiel (Ham-iel) Family. The family tree, if you and I are related, is partially in the hands of Mr. Morris Spektor (Spector?) in Hamden, CT. I believe he is listed in directory inquiries. Also, as I told Emily, there is a newsletter that I used to get. I think it is called, "Landsmen" or, "Landsman" and your bigger libraries would be able to find out how you could get an issue. If is for people whose ancestry comes from the Lomza/Bialstock area and who were Jewish.
The Danielewicz family could easily have been Catholic in origin, I just don't know.
The major occupations of this entire family line were in breweries and inns. I'd like to know more, myself.