Application using R tool

Hi,

I would like to make an application in Alteryx using R tool, used for running an R script that makes changes in a column (the number of the column is entered by the user) of some file. So at the moment I'm able to create an input data and link it to the R tool which holds the script. Then link it to the browser to see results. So I don't know how to pass the number of the column given by the user through the numeric up down to the R tool and how read this input inside the script. For clarify the idea:

Thank you