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.