Dear Zlatica Beca:
You are correct. Have a look at some of my other messages on the DZUPINA and JUPINA message boards. JUPINA, JUPENA, and (sometimes) SUPINA are all Americanized versions of DZUPINA. I have also assumed for some time that JUPIN is an Americanized version of DZUPIN.
My wife is a JUPINA (formerly DZUPINA). Her family came from the region around Velaty and Hrcel, south of Trebisov in the early 1900s. At least one other American JUPINA/JUPENA family came from villages just north of Sobrance between 1870 and 1920.
There is a DZUPINA family in Canada who also came from the region just south of Trebisov.