With the records written in Latin, normal name searches didn't work well, but luckily, surnames aren't latinized, so a broad search could still be done. The above image was found in the Parish records of Cappoquin, in the Diocese of "Waterford and Lismore". It is a baptism for "Joannem" (John) on 23 Martii (March) 1833. Though a year off from his own stated birth date, the parents names of Patritii (Patrick) and Honorae (Honora) are a match, and the mother's surname of Hyland can certainly be misconstrued as Helar or Helant.
I know that John had at least two sisters, Ellen (b. ca 1832) and Hannah (b. ca 1838-1842), based on Lowell, MA VR. I have yet to find either in the same parish registers for Cappoquin. I did find an Ellen baptised in 1830, but her parents were listed as Patrick and Honora Flynn. Nothing for Hannah has been found yet. There may also be a sister "Mariam", who was baptised in 1828, her mother shown as Honora Heelan (indexed as Keelan, though there are other Heelan names mentioned in same community).
No marriage records for a Patrick Condon and a Honora Hyland (Helar, Helant) has been located.
Below are two records showing the spelling variations of Hannora's maiden name.
National Library of Ireland: Catholic Parish Registers
NLI: Diocese of Waterford and Lismore: Cappoquin
Other blog entries on the Condon family:
Family of Patrick Condon
Condons of Creek Street, Portsmouth, NH