I NEED HELP>PLEASE

Hello.I need help from someone.I am developing a Role Playing Game in PHP.Im trying to make it so you can save and continue later.Each person will have a directory /$membernumber/.In that directory I need to somehow create a file save.php or save.txt or any file that can contain some text.I then want to fopen and fwrite the file with the info. If someone has ANY KNOWHOW on how to do this I would REALLY appreciate this.Thanks.