Austria of old http://users.erols.com/mwhite28/austhung.htm http://www.jewishgen.org/communities/loctown.asp
Čukovac locality 45°09' N 18°59' E E M U G Croatia 150.9 miles ESE of Zagreb 45°48' N 16°0' E
Cukovac populated place 44°36' N 15°27' E E M U G Croatia 87.4 miles SSW of Zagreb 45°48' N 16°0' E
What US documents have you located on ZIGIC^ ancestor?
Zigic, Mile Cukovac, Austria 19 1891 1910 Could this by your grandather's arrival manifest in NY Ellis Island?www.ellisislandrecords.org
Since the location is in Croatia, you might want to post on Croatia's board.
To get you started go thru www.croatia-in-english.com