First the code then i'll explain

page.php


page.tpl


I'll explain by line number because the p2l system strips some chars from regex

page.php
Line 2:
With that function we get the contents from page.tpl and store them into variable $file

Line 4:
Here we extract the data between <!-- BEGIN user --> and <!-- END user --> the regex matches all characters and symbold

Line 6 - 9:
Here we have the data that we will add between the <!-- BEGIN user --> and <!-- END user -->. This data can be extracted from the database

Line 14, 15:
Now we replace {USER} and {USER_ID} with the data from Line 6 - 9

Line 21:
With this function we replace all the data between  <!-- BEGIN user --> and <!-- END user --> with $data that results from the loop.

Line 23 - 27:
Here we replace the static vars with the text we need

Line 29:
Now we return the page :D

There might be spelling errors. If you have anything to add please contact me or post a comment.

File Download: page.zip