Location of data file on a web host domain that I own

     If you are the only user and aren't attempting to open the file from two or more devices at the same time, you might consider simply storing the file on a service such as Drop Box. I have a number of files where I develop on them on my office machine or my laptop--never the same file at the same time from both where I keep a copy in my drop box folder for that purpose.

     Try the "Cloud" as a single user, no domain needed.  Drop Box lets me use Phil's stuff easily without domain name, provided by Phil.  My Apple iCloud would do same as Drop Box... but it scares the non-believers[just joking Phil].  I have both Drop Box and iCloud.  I consider iCloud more Private than Drop Box,  but Drop Box offers similar security.  Windows has a Cloud too.

     Jim...

     Final thought on the "Cloud".  When set up correctly, the Cloud will Auto Update keeping the most recent copy in the "Cloud".  Thus allowing  many of your "peer to peer" devices to access the same stuff almost instantly.

     Thus...

     A song bought on an iPhone will play on your Windows computer when you get home, or you laptop while you drive.  Cross platform is not a problem.

     Jim...