Add an Address with Label to Send Coins Address Book via a RPC call Doing some ecommerce stuff 

Im not a c++ guy..I know in C# this is all doable 

Does the client support or could it support a RPC call on an open port to add an Address &amp; label pair with an Amount 

i.e ComputerWorld Order (5 x 7970) Order# 3340 100.5 BTC 

You could have an Do you want to allow confirmation yes/No

This would then allow a 1 step process for users top purchase goods online instead of copy paste etc
If you want to add a label to an address that is used to receive coins, you best use Accounts. Later you can fetch balances of individual Accounts and see which orders have enough confirmations.

If you want to add a label to an address you send your coins to, use "comment-to" field in an RPC call that creates the transaction.