Sankaran,
While i wouldn't recommend it, it's technically possible to make use of a delimited text file (such as a CSV) in ByDesign.
I've done this by creating a custom business object with an Attachment Folder dependent object that allows the user to upload a CSV file.
I then created a text parsing ABSL script to read the data and make the updates in ByDesign.
Again, i wouldn't really recommend it unless there is no alternative, but it is technically possible.
-Dan