Use the temporary measurements in dynamo

If you look at the picture, i marked a temporary measurement, there only is visible when i click the window.
Now, when i clicked on the measurement, i want to get that number into dynamo to process it. After that, i want to put another number in there.
So for example, in this case the length is 1194, and i want to get it inside dynamo and change the length to 1400, so the window moves. How do i do that?? :smiley:
A solution i found, is simply to copy the number into dynamo, process it, and copy the result back in. I just want to automate the coping process. Any ideas?? :smile: