At present there is not. Most TV’s do not support CEC volume control, and even if they did, Kodi has never supported this and AFAIK has no workaround for Kodi to alter this behavior.
You might have options for increasing the number of buttons your TV remote will send to the Vero however. You could install the Keymap Editor add-on and see what your TV is actually forwarding over the CEC bus. The following thread has the gist of what I’m referring to…