Best practice to save just one piece of information that might rarely change.

Hi.

My application will generate PDF's.     Those PDF's will almost certainly be always saved the same chosen folder.   But a different user may want to choose another folder.
So, what is the best way to save the file path (string)?

1) I could store the path string to a constant.    This is OK for me, but not for a non-programmer.  
2) I could create a  table with one record and one field.      If I wrote code around that, then the other users could change & store the information.  
3) I could create XML file.    But now, I would have to do some coding to handle a situation where the XML file was not there  (for various reasons).

Is there a better solution?