A symbolic link (also symlink or soft link) is a special type of code that contains a reference to another file or directory. So, it's like having a copy of the file in more than one folder, when actually you only have one copy of that file on your site.
Put the following code into .htaccess in /home/username/ (NOT in public_html folder).
Also, place the desired file in /home/username/ (NOT in public_html folder).
suPHP_ConfigPath /home/username/
order allow,deny
deny from all
Be sure to replace username with your lower-case cPanel username and replace file.name with the file's actual name.