You don't really need the vault code, that's just a shortcut. It's really hard to get to
the vault anyway. If you want to get the code and get to the vault, you'll have to get
slim, a pixel which i can't remember how to get to, because i beat that part a looonnnggg
time ago. Then you'll have to go up the the short right hand part of the second floor,
then use peach to use her parasol and fly over across the floor. Then you'll have to go
past the rooms, switch back into mario, and flip into 3d, you should know how to do both
of those things, because you've used 'em before. Then, go up the ladder, and flip back
quickly, bacause otherwise you'll take damage. You should reach to electrical bars, what
you'll need to do is use slim, walk into the area, and when the bars come near you use
slim untill you're not seeing your character, when the coast is clear, keep on moving.
Repeat as nessecary. You should reach the vault, enter the code and 1,000,000 rupe es
should pop out. Then go back across the bars, the same way you did before, go to mimi's
counter, give her all the rupe es, and you're done! Hope i helped!!