i know this is kinda late but this is what ur looking for
local LHand = -- However u get to the hand
local leftgrip = LHand.LeftGripAttachment.WorldCFrame
local WeaponHandle = --ur weapons handle
WeaponHandle.CFrame = leftgrip
local weld = Instance.new("Weld")
weld.Part0 = LHand
weld.Part1 = WeaponHandle
and since its welded just make your animations as if u had a 2 swords