Alena is a German-Czech female first name (from name Magdalena)

There are 5 places called Zelezna and 3 places called Beroun
located in the Czech Republic. Assuming direction and distance from Praha, probably Beroun located 31 km WSW and Zelezna located 28 km WSW of Praha.

Bohemia (including Moravia 1849-1918) was a kingdom (10th century-1918) and part of the (Österreichisch-ungarische Monarchie in German) or Austro-Hungarian Monarchy (1867-1918).
It was an Austrian Crownland.
Both German and Czech languages were used.

Mähren => Maehren => Marin => Moravia.
Mähren was an Austrian Crownland located East of Böhmen (Bohemia).
Its capital was Brünn (Brno).
Mähren had been a separate crownland until 1849 when it became a part of Böhmen (Bohemia) together with Österreichisch-Schleisen (Austrian-Silesia).

The parish church records are no longer in the churches but in the Czech State Archives. You can write the regional Czech Archives to research your surname (and pay their standard fees). Their extracts will be written in Czech.

354 surname Bartosh listed in SSDI (Death Index) and 630 surname Bartos listed in SSDI. Pretty common surname in U.S.

Ludina, Croatia is one of the placenames known to have microfilm records at the Family History Library (FHL) in Salt Lake City, UT.
These microfilm reels are available for rental and viewing at any Family History Center (FHC).
90% of patrons are non-Mormons doing surname research.

These records generally cover 1800 (and earlier) to 1914.

See link below for location of your closest FHC.

Frank Kurc^ina