I just got my family tree and I saw your posting. Charles Denis Lapierre was the brother of Joseph Denis-Lapierre and their parents were actually Pierre Denis-Lapierre and Marie Gaudin. They were married in Beaumont, on november 9, 1722. Pierre's father's name was Blaise Denis-Lapierre. He married Jeanne Laponche. They were maried in Ange Gardin wich is in Gascogne France.
If you wish to get more information on the denis-Lapierre family, wich is called only Lapierre now, feel free to contact me.