How to add arguments to command?

local groupID = 14041302

game.Players.PlayerAdded:Connect(function(Player)
    if Player:GetRankInGroup(groupID) >= 69 then

        Player.Chatted:Connect(function(message)
            if message == "!meetingtopic" then
                game.Workspace.TextPart.SurfaceGui.OnPartText.Text = "This is new" -- there change to second argument
            else
                return message
            end
        end)
    end
end)