Right, I'll walk you through it step by step.
1. Setup your RNG Reporter. I don't know how the newest RNG Reporter works for 4th gen captures, but I use version 8.31 for every 4th gen RNG abuse I do. Either way, make sure you have your seed in the right position, the correct method and syncer.
2. When you hit your delay and you have checked using the Elm Calls, note which answer he gave last and make sure you know which frame that is. Not that hard.
3. Now you know your target frame, and your current frame. Assuming you did 10 calls, will bring you to frame 10. As you said your target frame is 219. The total amount of frame advancements you have to do is 219 - 1 - 10 = 208.
4. You can advance your frame in different ways. I use the radio,
Elena90 used Chatter, which also works perfect. If you choose Chatter, you will have to do 208 Chatters in this case. No need to check anything, do 208 Chatters and encounter the Pokémon you're RNG abusing. If you use the radio, divide your ammount of frame advancements by 14. Every time you switch to your radio, it will advance 13
or 14 frames. 209 / 14 = 14. When you did this, you will probably not be at frame 208, or 207, or 206, but a bit further off. When you did 14 radio switches, you will be on a frame between 192 and 206. Now you start calling Elm again, to see on which frame you are.
5. Keep doing so until you reach frame 218 and encounter your Pokémon.