I have asked you kindly to refer to me as I prefer to be called, Richard. Please note: the Anglicized version of my last name is MacCumhaile. I invite you to try to make McCool out of that. Nevertheless, somehow it happened.
The article which Doug has recommended and which I have recommended as well, is entitled "Pieter Pieterse Lassen of Dutchess County and His Descedants." This was written by Donna G. Ewins, whose address is provided in the article as 8521 Porter Road, Apt. 51, Niagra Falls, NY 14304-1626.
For now, I will quote only her very first sentence:
"Anyone conducting research in the 18th century civil and ecclesiastical records of Dutchess County, New York, will quickly find references to a whole host of individuals named Lassen and Lassing, with these surnames evolving into Lawson and Lossing by 1800." (NYG&B Record Vol. 129. Number 3, page 149 (July 1998)).