How to create a script to rename topics ending in ".txt"?

I imported text files to create a help but the problem is that the extension of the files is also put in the topic name, I need a script that renames the topic names ending with ".txt" to remove this part.

Can someone make this script for me please ?

I tried to:

Rename all my text files by removing the extension then import these files with HelpNDoc but it doesn't want them!

I tried to find out how to rename topics in the help, but I can't find anything in the API help.

I don't know how to code with HelpNDoc, I don't know either the Pascal language !

I've tried to tweak some scripts but I can't do it.