Angle tween not working correctly?

I've used crazyman32's CFrame Tween and edited it so it works slightly correctly. My problem is that on line 2, if I don't add rs_Joint[3]* then it moves the part to the center of the character, but if I do, I can only tween it from a 0,0,0 angle, otherwise it screws up. I need it to tween from any angle to that one, though I can't figure out what to do

F.Y.I. I'm not very fond of CFrame...even though I've been using Lua for over 4 years..

coroutine.wrap(function()
    local NewCF=rs_Joint[3]*CFrame.Angles(math.rad(30),0,0)
    local oldangle=Vector3.new(rs_Joint[3]:toEulerAnglesXYZ())
    local oldpos=NewCF.p
    local newangle=Vector3.new(NewCF:toEulerAnglesXYZ())
    local newpos=NewCF.p
    for i=0,1,.04 do
        rs_Joint[3]=CFrame.new((oldpos*(1-i))+(newpos*i))*CFrame.fromEulerAnglesXYZ((oldangle.x*(1-i))+(newangle.x*i),(oldangle.y*(1-i))+(newangle.y*i),(oldangle.z*(1-i))+(newangle.z*i))
        wait()
    end
end)()