yes, it will import your address. your coins don't exist in any wallet, they only exist in the blockchain, where they are shown as belonging to your wallet. exporting your private key and importing it into the client will download the transaction history of your account from the blockchain(this takes a few minutes and the bitcoin client might become unresponsive but whatever you do, do not close it, just let it finish). then quit the client and restart. it will rescan the blockchain automatically. please note once you have restarted after importing it will take an abnormally long amount of time for the client to load(about 10 minutes on my T6400 2.0 GHz core duo 4gb) once reloading the client, you should see your full balance and transaction history of your address.