From a link I will include you will find that the Caumonts are not related, but that the Force line does indeed go back to France and some interesting people. There is even an online book about this.
See:
http://www.art-science.com/Ken/Genealogy/SB/scrap5.html for a piece by Charles Force
See:
http://www.art-science.com/Ken/Genealogy/PD/Index.html for the downloaded, free, book.
There is also much more on that site that pertains to Force family.