Attached is one way you could do it.
I took over the "tell X about Y" command, changing it to "tell X to Y". This allows you to use the current editor GUI to add "tell to" commands instead of "tell about" topics. To add topics, click on tom and then the Ask/Tell tab. Then you can go down to the "Tell about:" list and add what you want.
I'm not saying this is ideal or even the way you want to do it. But it is one way.
If you wanted both "tell about" as well as "tell to", you could add a new "tell to" command variant fairly easily. However, you'd have to edit the topics dictionary yourself since the GUI won't support both at once.