Writing Text To Internal Storage

Im trying to write a string to a text file on the phone internal storage

i use the following code

protected void writefile() {
String FILENAME = "filedemo.txt";
String content = txtMessage.getText().toString();
try {
FileOutputStream fos = openFileOutput(FILENAME,MODE_PRIVATE);

[Code]...

I understand this writes it to the internal storage in data/data but I want it to store in a folder called "Datafiles" which I can access via my PC or using a file manager.