Oh, I see.
With capturing Pokemon, it's all a matter of advancing the frame. It differs for each Pokemon, but the RNG guide gives details on what frame certain Pokemon start on.
To give an example, let's take Shaymin, which starts on frame one. Your target spread is, say, frame 101. So you subtract 101 - 1 = 100 frame you need to advance. Going to a journal page that shows a caught Pokemon advances the frame by two, so you would have to flip to those pages 50 times.
For eggs, the NPCs move at a very fast rate and advance the frame for you, so it's mostly a matter of timing. I usually try to collect the egg as soon as I can for a consistent timed frame.
I hope that was good. >.<