How to change scraper settings

[swedish cook]

This may be a really dumb question, but several hours googling and a helpful answer on xbmc forum and I'm still a little confused how to proceed.

What I'm Trying To Do
One of my sources of movies is an Enigma2 PVR, it creates recordings with a date prefix, such as "20130316 - Total Recall.ts"

What I found
Suggestion was to add the following directly below the <CreateSearchUrl ...> line in the relevant scraper file

Code:

<RegExp input="$$1" output="\1" dest="1">
    <expression noclean="1">\d{8}%20-%20(.*)$</expression>
</RegExp>

So Whats The Problem
I can't find the scrapers ... my system folder doesn't have anything in it and googling says thats where they are meant to be. I see some directories and xml files for what look like the scrapers under addons but those xml files have no "CreateSearchUrl" tags in them.

Confused - probably just me being dumb but if you could point me the right way it would be appreciated.