I have a quick look on the Interweb for free online writing courses and didn't have much luck..

However after looking at my old Uni there is maybe something that might help
Try http://www.open.edu/openlearn/ and stick "Creative Writing" in the search box

The main problem with courses is that tutors have a need for bright shiny coins of any realm because they tend to eat nothing but food... (And/or pay for naughty wimmin)