Canned responses for wordpress comments

Hi! I need to be able to add my custom buttons to the default WordPress response textarea so that I have my own canned responses. The idea is that when I click one of those buttons a custom text appears in the textarea making my response faster. It is very similar to what current buttons do, but expect of adding HTML tags like <b></b> I want to add a text, like Hello!

Does anyone know of any plugin that does that or can point me in the right direction?
Thanks a lot!