After five years I searched again and found the solution. It's is included in the docs but I couldn't find out back then.
In oscam.user for any user that should map CAIDs, I should include the following instruction:
caid = EEFF:0B00
that will map (redirect) any request that comes to EEFF into 0B00 for that particular user.
For more info see oscam docs and search for caid in oscam.user.