[Samba] special permission on directories

[Old Eduardo]

hello list,

im trying to configure samba, no pdc, just samba for share directories with
linux users.

my problem is:

i have users and groups

diretory1
diretory2

at directory1 group own is x
at directory2 group own is y

i make chmod 775 at directory1 and chmod +t, after i make chown root.x
same in directory2, just change chown to root.y

my problem: when user make directory and other user make one file at this
directory, owner and others users can delete files.

I need same as chmod +t when users create new directory, but dont work with
me.

Thanks in advance

And sorry for bad english.