[Samba] changing group ownership on a file from windows

[Rob Buhler]

Hello everyone.
I am using Samba as a PDC and am wanting to be able to change the group 
ownership of a file from windows.  Can or has this been done?  I am able 
to change the permissons on a file from windows (rwx- read 
write,read&execute), but when I try and change  the group (removing the 
current group then clicking on add to get the new group), I get the 
message "access denied".
Here is my smb.conf file... I have a share named test, with the group 
testwww, which I am
a member of. I have a txt file I want to change the group from "testwww" 
to "test" from windows by right-clicking on the txt file, properities, 
security settings.  When I do so,
I get a windows error message "access denied".
I would appreciate any suggestions.
thanks,
Rob

[global]
   password server = 128.187.115.154
   security = domain
   netbios name = webedit
   server string = Web Edit
   workgroup = EEAUTH
   encrypt passwords = yes
   mangled names = yes
   client code page = 437
   lock directory = /etc/samba/var/locks
   hosts allow = 128.187.114. 128.187.115. 10.8.116.
   domain master = no
   local master = no
   time server = yes

[test]
   browseable = no
   path = /web/test
   read only = no
   create mode = 0660
   directory mode = 0770
   valid users = +testwww

***********and in /etc/group I have the following lines*********
testwww:x:1097:james,rob
test:x:1098:james,rob