Thanks, archangel_617b.
I had forgotten about that possibility to change the .htaccess to read the file as .php !
But I believe there may be one problem with that approach -- if, for instance, the file in question is a .cgi file (or any other particular file extension) and I alter the .htaccess to read it as a .php file, then .htaccess reads all the files of that kind as .php files on the whole website (at least when I altered the settings through my control panel at hostrocket). If I leave it to be read as both a .php file and a .cgi file, I get an error message.
I think there is a way to change the .htaccess for each file directory, rather than the whole website (though I can't do that through my IP's control panel).
But the ability to make that change is perhaps a good reason to name a file with an off-beat extension (although it creates a little more work, it is also fun). Maybe I'll do that!