Do I can change LocalPlayer to my player in a global script?

I'm trying to do a script builder, instead of game.Players.LocalPlayer to game.Players.Xx_XSanderPlayXx.

this is what i tried

function Run(f, plr)
    local unfunction,message = loadstring(f)
    if not unfunction then
        return nil, message
    end

    local oldEnvironment = getfenv(unfunction)

    local NewEnvironment = setmetatable({}, {
        __index = function(_, k)
            if k:lower() == "localplayer" then
                print(k)
                oldEnvironment[k] = plr.Name
                return oldEnvironment[k]
            else
                return oldEnvironment[k]
            end
        end 
    })

    setfenv(unfunction, NewEnvironment)
    unfunction()
end

it only works with game.Players[LocalPlayer].

Can someone help me please?