Constant line on analytics pane

Hi all,

I wonder if you can help me with this issue, I 've searched this in the forum but I didn't find the exact solution.

So, it's regarding the constant line on the analytics pane. The software provide us the possibility of creating a constant line but just by inserting a value and not a measure. I attach here a printscreen of what I really need:

I have a measure created named as "progress of year" and I want a constant line based on that measure. As you can see in the printscreen I've put the value "0,2356" mannualy in the constant value in order to represent my need. This measure isn't related with the data on the graph, so I shouldn't use the other lines availabe as min;max;average or median to represent it.

If anynone can help me I would be very grateful

Regards