In RNG reporter, find the spread you want (Method J if DPPt or Method K for HGSS). Put the seed in where it needs to be, and set the IVs to what they're supposed to be (not needed, but it helps). Now right click on the first spread, and click Generate Encounter Slots. It will give you some numbers, with links under that. Click the respective game you're using. Use the find feature to find all encounter slots the pokemon you want appears in. If that frame has an encounter that gives you your target, that's the frame you hit. If it doesn't, go to the next frame (if there is one) and see it's encounter slots. Repeat until you find the frame that works, or if there's none left. If the later, sorry but you won't be able to use that spread (unless you feel like radar abusing).