I will do my best to explain in example...

say you have 10 mods selected when you load the launcher. You have added three more mods and want to put them into place without clicking a bunch of times. Look at the name of the mod you are activating to add, go look at your current checked list, find its order place in that list, untick the mod just below where you want it, tick the mod being added, click the up arrow now and it will jump up to the space above the top uncheck mod. Add the check back to the mod you unchecked to mark the place.

THIS ONLY works going UP. Going down you must click click click

Honestly, I went to the text file and hand sorted everything