I understand your point.
This is how I am going to build the application.
First, I will use Java for your project.
Second, there will be one text input to input the word to remove, one textbox to show the results of duplication part in the files, and one button to start "remove" and one button to cancel.
For this, we need to install JDK and I will use NetBean for your project.
The timeline is enough for me, so let's start your project.
I will support you 100% I can.
Thanks.