Again, I encourage you to look at [Link: remotecentral.com]; most of codes are there.  Look especially at Sound Field + and Sound Field -  (45518 and 44494).

Here are some additional (or duplicated) possibilities.
Amp menu 29391
Display 29647
Auto Format Direct 64975
Dimmer 53199
Memory 49615
Amp Menu/Tools 28110

Remember, you need to be using Setup Code 31758.  You can assign any of these 5 digit EFCs to a button using the 994 command just like you did in getting the OK button to work with the Vizio TV.
But read Post #2 in the above link.  It tells you how to test and assign the various functions.