About PF ECR Sheet

Dear sir
i am working in a real state firm as a Admin Executive but last week i also adopt the responsibility of HR Exe thats why i Want to know how we can convert an ECR( PF) Excel sheet into CSV file & CSVFile into TXT file, & Among these files in which file we use #~# formula .& how We use this formula,

Dear Reenapundir,
After preparing excel sheet save As it as with the file extension -CSV (comma delimted)(*.csv) then right click on that file go to open with then Notepad.Now open Notepad remove top line (headline line) you will find commas replace all commas with #~# and Save As it with common file extension as .txt now this file is ready to upload.