pico copier.sh

#!/bin/bash
# add your folders names
sites=( user1 user2 user3 user4 user5)
# old dir.
_old=/var/www/st
# new dir
_new=/your/new/path/with/out/accounts/usernames
####################################
counter=0

while [ $counter -lt "${#sites}" ]
do
    cp -r ${_old}/* ${_new}/${sites[$counter]}/*
    (( counter++ ))
done

chmod +x copier.sh

./copier.sh

raed@raed-desktop:/tmp$ ls -l /tmp/plugins/
total 0
-rw-r--r-- 1 raed raed 0 2011-03-26 17:40 1
-rw-r--r-- 1 raed raed 0 2011-03-26 17:40 2
-rw-r--r-- 1 raed raed 0 2011-03-26 17:40 3

raed@raed-desktop:/tmp$ ls -l /tmp/test/
total 28
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 1
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 2
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 3
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 4
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 5
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 6
drwxr-xr-x 2 raed raed 4096 2011-03-26 17:46 7

raed@raed-desktop:/tmp$  for dir in `ls /tmp/test/`
> do
> cp /tmp/plugins/* /tmp/test/$dir/plugins/
> done
raed@raed-desktop:/tmp$