In this answer, I used two hidden grey boxes, one after the other. However, I had some trouble getting them to format probably.
If you write
>! Line 1 >! Line 2
! Line 1
! Line 2
In order to fix this, it seems that you have to place some text between the two lines. For example,
>! Line 1 $ $ >! Line 2
Is this necessary? If so, can it be fixed?