Next Frame or Ctrl + N works. xD
Goody! Thanks! I'll email you the file.
In that file, it lists the frame number, then the corresponding PRNG State. It lists the SID you'd get on Emerald as well as the one you'd get if you were doing this on FRLG.
Basically when you get close to your target frame, pause the emulator and see what the current PRNG state is, then search the text file for the frame. If it's close, use Ctrl + N to advance frame by frame until you get to the target frame. Then, when you do, hold down Z (which is A button iirc) and unpause the emulator and then watch your avatar shrink and save inside the trunk and open your save file in Enciclopedia Pokemon or something to check your SID. If you didn't hit it, that's fine. You still have the save state, and 500 frames isn't that long a wait so you can do it over. Just make sure to check and see what frame you did hit so you can calculate what the frame offset was. I assure you, it prolly won't be all that big if at all.