Vertical Line in Column Chart

Hello,

Can somebody teach me how to make the vertical line like this (together with the label)?
I have the column graph as shown in the attachment. But I having difficulty in making the straight line and the label.
As far as I know, the label of the straight line (LLC, HLC) only can be done manually, that is, create a textbox and put it at the graph. Is there any alternative way to do it so that the label and straight line can be generated automatically when i define the value for the vertical line?