mounting filesytem for homedir

[Guillaume]

Hi,

i try to mount EXT3 partition in the /home/username directory but i'm
hae some issue with ACL.
here is the process i use to reach this goal:
 * create the user
 * check the ACLs on this directory ( /home/user 770 user:user)
 * check the group on the special file ( /dev/sda1 root:user)
 * mount the filesystem (fsttab => /dev/sda1 /home/backup ext3
iocharset=utf8,group,noatime )
 ->> fail... only user root can do this.
 * if i mount the filesystem with the superuser ACL on the directory
/home/user change and look like this : (/home/user 775 root:root)
   this is not good and i would like to have 770 user:user

Can you help me fixing this problem ?
many thanks.

-- 
Guillaume