Self modifying PHP script

[dark_hunter]

I'm trying to modify a part of a PHP script structured like this barebone example\[code\]<-- part A -->function modify_B($string){ some code to modify part B}<-- end A --><-- part B --> <container>some XML</container><-- end B --><-- part C --><-- end C -->\[/code\]I'd like to modify part B without changing the rest of the file, because A and B are the logic of the script which should not change.Could somebody help me?Thank you in advance for your help.