Limiting Data String to first End User Post

Content

I'm trying to create a report which pulls the customers first query when they come into the chat conversation. We want to include all data strings up until the Agents first response. 

We are trying to pull this information to start utilising these details to train a development bot. 

Are their any expressions, filters or variables I could use to refine this report. 

So far i have the report filtered on event type with chat ID, Event, and Data string for columns.

Thanks,