How to use agents response as an input to a topic?

Hi I would like to use the agents reponse to store it in a word or excel file. For that, I would like to use the response provided by the agent, pass it on to my custom topic which triggers an agentic workflow to store the agents response in a word or excel file.

I cannot sort out how to pick the agents response and pass it on to my custom topic, any help will be highly appreciated, thanks!