How to add pre processing on the data that is being loaded in Transaction Import Interface table in

Hi,

Please see if anyone can suggest me for the below scenario.

User will download the  Projects - Transaction Import WEB ADI document and will add the transaction import data and upload which triggers the standard import program  PRC: Transaction Import.

But in the middle i have to derive some values and populate into the interface table for the same data.

I have to populate some fields in the project transactions interface table PA_TRANSACTION_INTERFACE_ALL.

Can we customize the seeded Projects - Transaction Import WEB ADI and add pre importer rules in the webadi import section.....?

Thanks in advance. All the suggestions are eagerly welcome.