Script for count word in indesign save for file txt automatically named

When we write literary novels, it is common for many words to be repeated, but this is a mistake. So we have to correct this, change it to synonyms, or even correct the sentence. In indesign, I need to generate a file that counts the occurrences of each word, in each chapter, as I am using the "book" system, so each chapter is a document, and I want to generate these documents containing the list of word occurrences, and export to Excel, where I can view the words that appear most often in the text and work to fix my text, novel. I got a script, very good by the way, but it always saves in a single file name, for example it always saves in "capitulo.yxt", and when I run it again, it overlaps the words, but the same file name remains, so To make it easier, I would like each time I run the file, it would add "01" or "02" to the end of the saved file, so it would be something like "capitulo01.txt", "capitulo02.txt". I don't know if I made myself understood.