According to the Ford handbook , LOCK 10 means that you have had at least 10 unsuccessful attempts at entering the code, therefore it is now LOCKED and has to be taken in for recoding .
What might be worth trying is to disconnect the fuse or battery for 10 minutes, then reconnect and leave switched ON for at least 12 hours.(undisturbed ) This MIGHT allow another attempt to enter the code.(It does for other brands )...unless it has already been recoded.
Please post back here whether you are successful or not
If you do not know your code , post a new question.
Good Luck !
RegWorts, April 2008