Creating and uploading blacklist from Voluum to Revcontent

Hello, I present the following scenario: I have two campaigns promoting a products in the same niche and I want to make a blacklist with widgets ids from both campaigns and upload them to revcontent as a campaign blacklist. What is in your opinion the fastest and most efficient way to do so, and should you recommend just to organize them in a excel file please let me know how to list the widgets so its readable for