Hello again Francois
Well in a word, 'yes'. There are OAB APIs which will theoretically allow you to set up Flex ben info - if you have access to TOAD or similar, use a 'dictionary' window to look for packages of the form 'BEN%API'. If you do it right, the creation of the participant rate value will automatically generate the element entry. That is sometimes a big IF...
You're probably aware that Metalink has documentation on the subject of migration of OAB. All I would add is this: If you are doing an OAB migration, make sure that you pick the right strategy and stick to it! Also, bear in mind that several of the APIs are, shall we say, 'a little immature'. Check out the various OAB threads in the other topic headings on here...
I'm not sure I've helped here, but maybe some of our other OAB-experts might chip in.
Cheers
Clive