How to show a value in a line that comes from a different expression

[#1]

Hi everybody, I have a line Chart  which shows the amount of customer debt every Year&Month

The green line is the the customer Debt and the red dots with numbers come from another expression which displays the difference of the debt between the previous and the current month. This expression is:

Debt-Above(Debt)

What I want to achive is to display this number but in the green line, even when they are different expressions. Where the red crosses are.

Thanks in advance.

[#2]

Hi Pedro,
I got the result by removing the symbol from the difference.
Regards.

[#3]

Hi Corrado, have you changed anything more? I've done what you said but I can't get it. See..

[#4]

Hi Pedro, I post to you my complete QVW. Regards