How i read one line at a time (from a CSV file) using Staging in Oracle ICS?

Summary

How i read one line at a time (from a CSV file) using Staging in Oracle ICS?

Content

Requirement:

1) Upload a CSV file from a FTP location (onto ICS)

2) Use Staging functionality to read through the file (one line at a  time) and Transform some columns. e.g. add a new columns in the end (which is the locaiton of the row in the file e.g. 1,2,3)

3) Write the new file to the FTP location (with the new column added to the end)

What I have tried?

1) Upload to ICS, Used FTP adapter with "Download to ICS" function  (works)