I was automating a bunch of other stuff so I thought I would automate this also.
Using the Unix2dos command mentioned above; I now press F12 (open terminal in current folder) and type csv.
This is aliased to 'unix2dos *.csv' which is much faster then re-opening the files every time. I have tested that unix2dos doesn't do anything weird to the file if it is run more then once on the same file.
Notes:
Getting F12 to open a terminal in the current folder.
go to ~/.local/share/nautilus/scripts add a scripts called whatever (Terminal)
in the script place
# !/bin/sh
gnome-terminal
Then go to ~/.config/nautilus/script-accels and add the shortcut you want; I set F12.
F12 <script name> (Terminal)