There are restrictions of the filenames for matlab-functions, and as far as I recall it is supposed to not start with a number (I couldn't quickly find the documentation for this, but you should be able to search for this. In my work I also stay away from leading "_", so start with [A-Za-z]). So try to put the number somewhere but in the leading place. Also make good use of the fullfile, filesep and fileparts functions - they will make your functions and scripts more portable across different OSes (this might seem like a remote consideration from your perspective - but if you're lucky and your programmes becomes useful enough this is a major gain when you get users on all sorts of environments...).
HTH
