I am not sure if it is possible to locate the row using rowid that easily. I had similar problem sometime back and posted a thread here. Besides Rowids are present in the index.
One way is unload the whole table and then load replace with a DISCARD DD card with enforce yes. You will get all the bad records there in DISCARD file. And can decide what to do with them and change them if needed and reload this corrected bunch with load resume.