Get Row from Datatable

After much valued help received earlier, im stuck … again…

So I have added a read.csv in and i need an e-mail address looked up in the data table and to return a value.

The value returned in the output will be used to create a folder structure.
The assign “Client” contains the e-mail address to look up
The table from the csv, the email address is column 0 and the returning item is in column 3

You have not mentioned what is the problem you are facing ?