This is certainly a dirty workaround, but I figured out a way to do this thanks to @slhck's tip about locales. If a better answer comes along that would be more helpful to others, I'll certainly accept it since this pretty much only works for my specific problem.
I set the locale to Spanish (Bolivian) so that the commas were treated like decimal points, then standard numeric sorting did the trick.
$ export LC_NUMERIC="es_BO.utf8" $ cat test.csv 100,00869184 6492,8361 1234,31 200,04071 $ sort -n test.csv 100,00869184 200,04071 1234,31 6492,8361