How would I make the beam part only change size forwards instead of both ends?

I've been trying to figure out a way to do this for like 2 days now. I tried bodyvelocity, position, CFrame, and lookvector to make the part move forwards to make it look like it's only changing size in one direction but nothing works.

ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(player)
	local righthand = player.Character.RightHand
	local humanoidroot = player.Character.HumanoidRootPart
		wait(0.5)
		local Beam = ServerStorage.BeamPart:Clone()
		Beam.Parent = game.Workspace
		Beam.Anchored = false
		Beam.CFrame = righthand.CFrame + humanoidroot.CFrame.lookVector * 1.5
		Beam.Parent = game.Workspace
		Beam.BrickColor = BrickColor.new("Bright orange")
		Beam.Size = Vector3.new(3,3,3)
		Beam.Material = Enum.Material.Neon
		Beam.CanCollide = false
		Beam.Massless = true
		Beam.Transparency = 0
		local weld = Instance.new("Weld")
		weld.Part0 = righthand
		weld.Part1 = Beam
		weld.Parent = Beam
		for i = 1,10 do
			wait()
			Beam.Transparency = Beam.Transparency + 0.1
			Beam.Size = Beam.Size + Vector3.new(0,1,0)
		end
end)