How to parameterize different fields in one single datasource

Hi:

You understood it perfectly. 

Just to clarify, does the order of the values in the text file correspond to the order in which I add the properties?

For example, if the properties I added are in the following order
firstName
lastName
displayName

Then in the txt file:

John,Doe,John the Doe -- firstName
Max,Roach,Cockroach -- lastName
foo1, foo2, foo3 -- displayName

Thanks for your help,
Li