Usually, people use the
Volume Punch Through feature to control the TV's volume. In short:
Setup until 2 blinks-993 (2 blinks)--Press TV.
Regarding reassigning buttons with the 994 Command, it is important to distinguish between an OBC (also called function) number and an EFC. The spreadsheet you've linked to lists OBCs for many LG TV functions. UEI (the maker of Atlas and many other remotes) wanted to allow people to customize their remotes but without letting other companies copy their remote database. So they chose to encode the OBCs. You need to convert OBCs into EFCs before manually programming the remote. The JP1 community was able to decipher the EFCs, but the algorithm isn't easily done mentally. The straightforward process is to use
RemoteMaster and one of the many LG upgrades. Or you may be able to use the
Lookup Tool to find common EFCS.
So the OBC for Mute is 9, but the corresponding EFC is 00057, assuming the remote is using one of the standard LG setup codes.
Power is 00053.