According to the Shtetlseeker, Kozmin (Koschmin) was in the province of Posen in 1900.In 1930 it was in the province of Poznan.In 1999, it became part of the Wielkopolskie province.
Go to this site:http://www.jewishgen.org/Communities/LocTown.asphttp://www.jewishgen.org/Communities/LocTown.asp.Type in Kozmin.Indicate you are researching in Eastern Europe.Use the "Is Exactly - Town name with precise spelling" feature.Click on "Start the Search", and you will find four places named.One has a large icon.Hover your curser (arrow) over it, and you can read some of the information I found.
To search Polish records, you need to know a person's religion and place of birth.Records are filed by the name of the religion and parish.Most times the gmina (administration district) is where the parish is.The Kartenmeister tells us the Lutheran and Catholic parishes were in Koschmin (Kozmin), as well as the civil records.This means the gmina was also Kozmin.
German Name Koschmin Alternate Name 1: Coszmin 1561 Today's Name Kozmin Kreis/County Koschmin Residents of Jewish Faith 312 German Province Posen Today's ProvinceWielkopolskie Location East 17°27' North 51°49' Location Description This village/town is located 43.8 km and 280 degrees from Kalisch, which is known today as Kalisz Lutheran ParishKoschmin 1905 Catholic Parish Koschmin 1905 Standesamt/Civil RegistryKoschmin 1905 Gemeindelexikon/Town Index V-16-2 Population By Year/Einwohner 1905: 4164 Church Yes
If you do not desire to do your own research, you can have that archives in Poland do it for you.This is their site to see what records they have available:http://baza.archiwa.gov.pl/sezam/pradziad.php?l=enhttp://baza.archiwa.gov.pl/sezam/pradziad.php?l=en.Find Kozmin and click on more at the end of one of the lines for the records you want.There you will find their contact information.