@colegl and @phil-tanguay, I implemented this today for Google Assistant. I'm working on Alexa now.

I put this in my Voice Reply field of my Notepad command (I should have just created a new command):

Running {{trigger}} on {{computer}} with params {{params}} with result {{result}}

I put this in the Command field:

%USERPROFILE%\.TRIGGERcmdData\sendresult "My command result"

I said this:

Ask trigger command to run notepad with parameter russ

Google Assistant said this:

Running notepad on DS with params russ with result My command result

I'm pretty happy with how it turned out.

I only gave about 4-5 seconds to send a result via that SendResult.bat script. If you take too long, it will say "no result" in the {{result}} placeholder.

EDIT: Now you can do this with Alexa too.