How to integrate php script into livestreet?

Question

PHP

Hello.
There is a site on livestreet.
There are records on it, in each record additional. field - price (type xxx rub., or yyy usd)
There is a third-party php script that calculates the total cost of all records. That is, it makes a request to the database and sums up the value of all the "price" fields.
Also, if you enter a user id, the script can show the cost of records of a particular user.
Script sources:
https://yadi.sk/d/oCKRIipVYRHRy
How to make this script work on livestreet? And how to register a function so that the user's id is automatically determined on the user's page and, accordingly, the total cost of only his records would be displayed.
Tell me please.

Answer 1

As an additional module or extension of the functionality of an existing one.
see documentation .