Reading and appending text files
So I am starting to create a program that will be a multi step process. The principle is that the programming I am creating is to help our field engineers quickly add some lines to an text file that our main program uses for settings. I want to take the text file and append it to a new file until the line <settings> is found. From there I will do another step to append the new lines need then continue, but I am stuck on getting it to go into the array up to that line and to be honest I am not sure where to begin. I've been looking through the net but brain is now mush. Any advice, help, suggestions or examples would be appreciated.
Thanks,
Vendetto