Excel - Line chart with reference values

I am ploting a serie of data points using a line chart. I want these data point compared to a fixed minimum value, maximum value and target value. The only way I have found to draw the min, max and target lines on my graph is to have a column for each with the same amount of data as my data points in my source table. It is a bit annoying and I'd rather have an option in my graph where I set a min, max and target value and they appear as traced lines on the graph. The data points of my original serie may be out of these limits so I don't want to change my graph axis parameters. I have a graph example that I can send if needed.