need to edit text from within my application.

OK, I'm writing a little app that will edit a configuration file for the end user. I've written the GUI, as well as most of the other outlying code.

The problem is the core of my application -- the ability to either copy text to a buffer, edit certain parts of it, and write it to a new file -- or copy each line of text to a separate variable, then edit each variable separately (if at all), and then write all the variables, in order, back to a new file.

Memory is not an issue here -- if your running the application which uses the config file, you have enough memory (application in question is a game which uses a lot of RAM).

anyway -- I can copy the text file to a string, thats no problem. But once it gets there, I need to edit specific parts of it.

for example:
on line 12 it says: option1 = 0;
I need it to be changed to: option1 = 1;
and I need to change it without changing lines 1-11 or 12+

I've thought about using Python or LUA to do this for me, but the problem is that someone who is primarily a gamer using the Windows XP OS (my target user) probably won't have an interpreter on hand.

If this is a more viable route, and there is an easy way to include an interpreter or DLL to run the script within my installation package, I can also go this route (although, even though I have the development tools for python and LUA, I dont kow any code for those languages -- Id have to learn)

if any more info is needed, please ask.
thanks in advance.

Code:

---

  string option_old = "option1 = 0";
  string option_new = "option1 = 1";

  //option_new could be input by user
 //string option_new;
 //std::cin>> option_new;

  if{

  int search = datafile.find( option_old );
  if ( search != 0 )
  datafile.replace(search, option_new.size(), option_new);
}

---

Then again, you may be talking something completely different here....

Uhm... put each line into its own string or data structure and edit it seperately?