Variable to point to external URL?

I am linking out from my WP site to another website where my images reside. At this point I am fully qualifying my links to my images – “https://xxxx.xxxx.xxx/xxx.jpg” Is there a way to store in the php.index or somewhere else the path for my images? Can I just store the “https://xxxx.xxxx.xxx/” so that if I move my image store, I will only have to change the path in one place. As always, thanks in advance.