As far as I know, French regiments didn't have nicknames. They were named either after the region they were raised in ("Berry", "Languedoc", "Guyenne"...) or after their owner ("La Reine"). "Royal Roussillon" would then mean that regiment was that of the Roussillon region, and was property of the king of France.
You can find a list of the units from the Troupes de terre regiments (regulars) that served in North America during the Seven Years War here
. This website
also has a comprehensive listing of all the French army units of the 18th century (regular infantry regiments are found on this page
). No history of the units on both sites, as they are about uniformology. I have tens of bookmarked links, I'll go through them to see if I can find something else.
EDIT: You may also find information there (Canadian military history gateway
) but you'll have to dig a bit, as my browsers (IE & Firefox) seem to have problems handling it. And I just stumbled upon that page
. It's a brief presentation of the French army of the 17th and 18th centuries, that happens to be the work of one of my former thesis directors! It's very straight forward and doesn't give anything that we don't know already, but the organisation part is quite interesting.