Compare 2 files (Diff)

Need a script that will do the following:- I have a configuration file (which will be the default template) I have some other configuration files as well. I need to compare only specific lines (eg: say it has 100 lines, need to compare from 10-23 lines then 40-70 lines then 82-97 lines) from the default template to the other files. The bidder who will do the work fastest will be awarded the project.