 So you want to add a target line to your bar chart. All you need to do first is ensure that the data populating your bar chart is first a table which you can do by hitting control T and selecting okay. Next you need to make sure you have a cell containing your desired target value. Return to your table and create a new column called target. The formula simply equals the value or the cell containing your desired value. Hit F4 to ensure all rows refer to that same row. Select your chart, go into chart design, chart chart or change chart type. And then if you go to combo, you can see by default, Excel has already identified this is the visual that you would probably require. If not, you can simply select line from your target series, select okay, and you now have a target line added to your chart that dynamically updates as soon as you change your target value in the given cell.