i need old php version

[dracula]

I am using ubuntu 16.04 and vestacp. I have php 7 and wordpress installed on my site. I want to create a directory on my website and install vbulletin 3.8.2 into that directory (eg website.com/forum but I want wordpress to use php 7 but vbulletin in the folder should use php 5.2. Is something like this possible?

If such a thing is possible then how can I compile php 5.2 or add it to ubuntu from packages?