create connection limitation shared folders

I have a Vista pc with 5 shared folders. Other computers within the local
network can reach the folders without account because they are shared for
the Guest account. That works perfectly fine. What I want to do is limit the
total amount of connections to the shared folders of my computer. So that
for example only 5 computers can use my shared folders at a certain moment
with the Guest account. Is this possible? (I can limit the amount of users,
but they are all using the same (Guest) account.)

Thank you in advance,

Tim