@Tyler S Not without scripting. What I normally do is to CSV import and update a custom flag on the leads you want to set a response for, then create a dynamic group containing those leads - after than, just create an "Other Event" campaign to this group, and set it as execute. Just be aware that the response date/time will be when you run this.

Could you elaborate on the "Other Event" campaign part? I haven't worked with groups before but am generally familiar with campaigns. Is that an option within groups?

It's a Campaign Event, you basically just need to run any event other than email and this will then assign the response of Sent to each customet

Okay. Thanks!