chattr immutable

Hi,

I have a FC4 box with a Samba 3.014. There is one large share 
configured. I wanted to make a folder within that share un-deleteable 
but also allow smb users to write files to the folder. I tried

mkdir myfolder; chmod 777 myyfolder; chattr +i myfolder

Then from a windows box tried to delete the folder and got permissions 
denied, so far so good. They I tried to copy a file to the folder and  
was denied also, not so good.

I have tried a combinations of +i +a but I can't get the desired effect. 
Is what I am attempting possible or should I create a new share and use 
smb.conf to administer the file permissions?

TIA,
Dp.