Robert already told that this is SELO LUKOVO (Village Lukovo). There is Lukovo on the Adriatic coast and there are lot of Rogic families there indeed. What I wanted to say here is that Lukovo is very common name for places in Croatia and there are really lot of Lukovo villages all over Croatia. It could be that your folks were from some small village called Lukovo near Kostanjevac(maybe the parish patron was St Luka - I’ve noticed that Joseph’s son and brother were named Luka).
Besides, I’ve seen in the phone book that Rogic and Plantek families still live in Kostanjevac, Berek, Ploscica and surrounding places. If you like I can send you address of all this people so you can contact them and clear all this regarding Lukovo and all other stuff you’re interested for.