This depends on when you are trying to extract this information, and from what.
Assuming you mean a message that is in your mailbox (i.e. a message you have received), use the Message.Recipients collection to iterate through each Recipient object. Each Recipient object has a property TargetType, which indicates the type of recipient you are dealing with. Possible values are:
0 – To. A primary recipient.
1 – Carbon Copy. A secondary recipient.
2 – Blind Copy. This address is hidden to all users except the sender and the receiver.
I hope this helps. Please let me know if I have misinterpreted your question.