Anil,

Welcome to SSIS! This article admittedly covers a more advanced topic and is not geared for SSIS beginners. Here is some reference material you may find helpful. I also encourage you to search and participate in forums on SQL Server Central. There is a lot of great information for SSIS beginners.

- Tutorial: Creating a Simple ETL Package: http://msdn.microsoft.com/en-us/library/ms169917.aspx (Lesson 1, Step 6 covers configuration of a Lookup Transformation)

- Lookup Transformation: http://msdn.microsoft.com/en-us/library/ms141821.aspx

- Extending the Data Flow with the Script Component: http://msdn.microsoft.com/en-us/library/ms136118.aspx