use htaccess to upgrade PHP?

PHP and htaccess question. Hello, looking at my phpinfo() i'm using this version - /usr/local/lib/php-5.6.30-precise When doing a loop over the /usr/ directories, I have access to :- 80' '/usr/local/lib/php-7.1.20-precise' 81' '/usr/local/lib/php-7.2.15-xenial' 82' '/usr/local/lib/php-7.2.9-precise' 83' '/usr/local/lib/php-7.3.2-xenial' 84' '/usr/local/lib/php-7.4.9-xenial' 1) What is the difference between precise, and xenial versions of PHP ? (Ive googled & found Xenial is some version for a linux Server). phpinfo also confirms Linux server. Whenever I log into my portal (shared server with other users/websites), it tells me to upgrade my PHP. HOWEVER if i do that, it affects my ENTIRE website (multiple sub domains & the main directory.) I'll have to upgrade, & then quickly review each of my sites for any broken pages. I can't change each subdomain one at a time via the portal. 2) Is there a way to use htaccess to change the path, & which php version to use ? I'll then create a new subdomain, Copy my files over - (Removing excess code I dont need) and use the newest PHP version. Is this possible in htaccess ? When I have my two main websites/subdomains transferred over, I can just upgrade the PHP in the main portal. if possible, I'll be able to upgrade each of my subdomains one at a time -- Gordon.