CRFox,

We’re glad that you were able to locate the appropriate registration code. For future reference, however, this would be an issue to bring up with Steam Support, as the problem you were experiencing was locating the appropriate code in the Steam Client itself. Steam Support can be reached through the below URL:

Steam Support

While this post is not expressly related to technical issues for FINAL FANTASY XI itself, we’ll leave it up for now as it is an informational post none-the-less.