Vista - Vista to XP network permissions

I have just started to try making use of Vista's ability to set permissions
on network shares and can't quite do what I would like to - I'd be grateful
for any help.

I am trying to share folders on my home network in a particular way but am
not sure whether it is possible to do what I wish?

I have a Vista Home Premium computer with 3 folders that I want to share,
the Public folder and two other folders. The other computers on my home
network run XP Home and I would like all of them to be able to read, write
and create folders in the Vista computer's Public folder but only one of the
other computers to be able to read, write or create files in the other two
shared folders.

Is it possible to do this? If so, then how?

If you find out, please let me know, I'm having the same problem.
Cheers