Hacking In which file is Friend Code stored?

[skodave]

Hello, I'm trying to remove the friend code (like it was never requested) from a savegame of Animal Crossing but I can't find where it is stored.
I decrypted/uncompressed the file "data.bin" and looked for the code with an hex editor in the following files:
rvforest.dat
wc24dl.vff
wc24pubk.mod

Is the friend code for this game (or usually) stored in a "system" file? Can you point or suggest me the file/s please?

Thank you in advance