Line 3 has a comma in it, which shouldn't exist. Line 4 is also wrong, since move is the first move, not all of them. I was only being colloquial with my description, as I assumed you knew anything at all about coding (or could at least read the wiki to find out how a moveset worked), but if you want I'll give you some actual code.
Search your scripts for the phrase Events.onWildPokemonCreate.trigger. If it exists anywhere, that's perfect, and you can follow the wiki's instructions on how to modify the Pokémon (but instead of making it shiny, edit the moveset instead).
If it doesn't exist, then go into the def pbWildBattle just after the line genwildpoke=pbGenerateWildPokemon(species,level), insert some code along the lines of "if $game_switches, genwildpoke.moves=PBMoves::HYPERBEAM, etc.".
Either way, you'll need to turn a Global Switch on and off immediately before and after the battle.