Wlikinson/Cullen families of Dublin

Are there any search angels from the Dublin area? My 3rd great grandfather came to Canada to fight in the war of 1812. His name was Patrick Wilkinson and his father was Thomas Wilkinson and mother was Elizabeth Cullen. I have found entries for his siblings Michael, Thomas, and Anne, but cannot find any trace of Patrick. He was born in 1798 and I believe was baptized in St Nicholas' (Without), Dublin City. Can anyone help with this family? I find no trace of the Cullen clan either, though they may be married into the Bulger clan of dublin. Just a guess, but I think Elizabeth had a sister named Catherine who was married to a James Bulger.