So I was thinking how could I convert Vector3 to UDim2?

This is the script I use now... tho it doesn't work.

plr = game.Players.LocalPlayer
chr = plr.Character
while true do 
    wait()
    script.Parent.Position = chr.HumanoidRootPart.Position
end

So I want a frame to move as character moves, tho I can't do it cause gui uses UDim2, not Vector3. So I was thinking is there a way to covert Vector3 to UDim2.