[Samba] double share?

[Erik M Stokhof]

Hi all,
I have a setup where a linux box mounts an SMB share from another computer, 
and then shares that mount in turn.

Is there any way to make the mounted share writable by visitors to the linux 
machine?

Why do I want this? We have an NT4 machine that runs a database, and people 
need to synchronize with the database over the Internet. Since VPN 
implementations currently do not work, I need a workaround, and one of the 
possibilities is a shared server setup, where both sides of the 'firewall' 
(I hesitate to call it that) can write to the same database without needing 
full LAN access to the outside.

Again: Is this possible?

Thanks in advance,

-Erik