How Do I Convert ECR Sheets and Use Formulas for My New HR Role?

I am working in a real estate firm as an Admin Executive. Last week, I also adopted the responsibility of HR Executive. That's why I want to know how we can convert an ECR (PF) Excel sheet into a CSV file, a CSV file into a TXT file, and among these files, in which file we use the #~# formula and how we use this formula.

After preparing an Excel sheet, save it as a .CSV file (comma delimited) by selecting "Save As" and choosing the .csv file extension. Next, right-click on the file, select "Open with," and choose Notepad. Once the file is open in Notepad, delete the top line (headline line) containing commas. Replace all commas with #~# and then save the file with a .txt extension. The file is now ready for uploading.

Thank you.