Hi,
yes, just create those subdirectories and the file and just paste this line and any other language strings into the file, which you want to be replaced, each on a new line.
And, as always, save your file, don't forget to clear the cache in your dokuwiki\data\cache and refresh or restart your browser!
To clear the cache, there are several methods around. I prefer to delete all the folders I find in dokuwiki\data\cache.
Cheers!