The command you want is: importprivkey "Priv key here"
That will then put the private key into your wallet.dat and rescan the blockchain looking for transactions associated with that private key/address. Your transactions and coins related to that private key/address should then show up (assuming your Bitcoin Code is synced up until the point in time the transactions were confirmed)... If it is 14 weeks behind still... it won't be able to show transactions from 3 days ago
wallet should certain private key,so it well be no error returned and code.transaction will be applied secret key and bitcoin needs blockchain to be transact to their own private key to make avoid of missing