When using PokeRNG, you can either set it to method 1, breeding, or which ever one that is used by Emerald. It doesn't have wondercard, method J/K, or any other the others as options. But any Method 1 spread is also avaliable in Wondercard, so once you find your seed, put it into the RNG Reporter and set the method to Wondercard. Then find the frame you need to hit, and abuse the egg.