May I understan your mean like this:
If a wallet of XXXCoin has two address 123xxxxxxxxxxx and 456xxxxxxxxxxxxx and
1000 coins with the address 123xxxxxxxxxxxxx
0 coin with the address 456xxxxxxxxxxxxxx
then I can't withdraw from the address 456xxxxxxxxxx even 1 coin ?
If 123xxxxxxxxxxxxx and 456xxxxxxxxxxxxx are ACCOUNTS, then you are correct. Addresses are independent to accounts, and there isn't a 1:1 correlation between them; you can assign multiple addresses to a single account.
Are you in the process of setting up an exchange ?
Yes I am
can you help?
A word of advice for setting up an exchange; accounts in bitcoind don't scale up that well, and it will be both faster and more secure if you use a database to keep track of balances and just use bitcoind for transferring coins into or out of your exchange.