If I am visualizing this correctly, you want to add another treatment over top of an existing one, but essentially a "grad" tracking with some object or horizon line or something.
I'd add a key output to the window node so the qualifier for your "master" secondary is available to a following correction node and use either the line/arrow or square generator to create the grad. You will probably need to copy the tracking info from the master qualifier and paste it into the grad or re-track it and hope its the same. The key will be acting as a Boolean operator.
"I always pass on free advice -- its never of any use to me" Oscar Wilde.