"Negative" spacing

Problem:
I just wrote down some choir notes. I used two lines with two voices each (S/A and T/B). The problem arises when adding the songtext: Sometimes the text applies only for S/A (i. e. the upper line), but sometimes for both of them. In this case I don't want to write the text twice but place it in the middle between the two lines. Thus, I needed a feature to change the spacing between the songtext and the line below for just those particular bars/systems. I know that there is a feature to ADD extra space between lines, but in this case I'd rather like to REMOVE it.

I used to write scores with capella. There you can add extra space per line via context menu. Negative values are also allowed, so this is how I did it with this program.