How to draw Lines on a 2D Clustered Column Chart in Excel

[Boodog34]

Hi Wondered if anyone can help. I'm trying to draw horizontal line on a 2D column chart. 

When I try and 'Add Chart Element' The option to select' lines' is greyed out. Is that because of the type of chart I am trying to use? 

Anyone any idea how I can draw straight horizontal line at certain value on my column chart? 

Thanks in advance.

Boodog34

[#2]

@Boodog34 

Add data to the source range with the value you want.

Add this as a series to the chart.

Select this series.

On the Chart Design tab of the ribbon, click Change Chart Type.

Change the type of the new series to Line.

Result: