I have an upcoming flight this week on Iberia booked as an AA codeshare. As always, I like to double-check my reservation on the operating carrier's website, as well as possible seat selection, flight notifications and OLCI. However iberia.com does not recognise AA's record locator (as ba.com does now) so I called AA EXP desk to get the Iberia booking reference; first agent gave me a reference but it was only five characters and iberia.com requires six. Called back and second agent says there is no Iberia booking reference because it is an AA codeshare!
Called Iberia and they gave me a different booking reference which was again only five characters and does not work on iberia.com
Tried checkmytrip.com which does not recognise AA record locator, and requires six digits.

Has anybody else had this problem, and is there any other way to find a valid Iberia booking reference?
Thanks.

Happy Travels.