If I understand your question correctly, you are just looking for a way to include PHP files in other PHP files. There are a couple different ways, like include or require (as well as include_once and require_once, although it sounds like you’ll be referencing the same file more than once possibly), both of which basically just bring an external php file in as if it were part of the file you are referencing it from. Here is a description on the differences between the two.
