You really don't need to do that, and, just out of curiosity, how are you making those lines?
There shouldn't be any need to composite them in post work at all.
If your camera is looking North(say), then just offset the transform shader's translate Z field by a few hundred metres negatively(try increments of 100m in the direction you need to move them until you have the right setup). If you're looking East(say, again

), the same applies, but in the X field. You would certainly be able to move those lines without
any outer PS work needed, I can guarantee that.
Maybe you'd like to post a .tgd here, or in private, and we can get those contrails moved for you in a few seconds, and never mind the PS work afterwards. I'd be more than happy to help out.

Indeed, if you're determined to do it yourself, that's cool, but fire a PM this way if you want any help, without needing to reassess and composite the scene after rendering it. I'd be glad to help and keep it all TG, it's just easier that way and next time you'll be able to DIY.
In most of these type of cases, postwork needn't apply at all.
This's the thing about TG2, and it's a shame, the instructions/documentations on such things are sketchy at best, but it isn't hard to do what you need here without post processing. Give's a shout if you need to, I'm more than happy to help out.