If you have ancestors from Háromszék (particularly the villages around Készdivásárhely), your family name may possibly be found on the surname "want list" of our Hungarian Bukovina y-DNA project
http://www.familytreedna.com/(crejjz45lzxe54b2g0zj3vjm)/surn...The five Bukovina villages are Andrásfalva, Hadikfalva, Istensegíts, Fogadjisten, and Józseffalva: most of the people who settled there in the 1780's are of Transylvanian origin.
Beth Long