If you are using an ir blaster then you are probably limited to the commands that are on your remote control. This means that probably you can't send a command like set volume 20, but are forced to use volume up and volume down. Similarly, you probably don't have access to a power on or power off command, but are forced to use power toggle. I don't even know what you receiver you have so I can't tell you much more than this.
If you need help with either VC or EG let me know. You probably want to have a voice command like "volume up <1-10>". The repeating can me accomplished in either VC or EG but it is easier to do in VC.