Inverted master-detail relationships (Forms 4.0)

SQL*Forms 4.0.

         How can I define an inverted master-detail relationship ?

The normal MASTER is the block based on the table which contain the PRIMARY key,
the normal DETAIL is the block based on the table which contain the FOREIGN key.

  I need to reverse this built-in mecanism to define a more global master-detail relationship.

  The purpose of this relation:

• From a record of a table A ,
• through a 1-n / 1-n association ( => implemented with a table B ) ,
• I want to get in a detail block the associated records of a table C .

     ___ 1-n 1-n ___
    | A | --(B)-- | C |

• ---

We can easily define the following relationships:

          A     C		= two masters
           \   /
             B		= one detail, the association ( ridiculous )

But how can I easily (or quickly) define this relationships:

          A	= the master
          |
          B	= A's detail, C's master ( hidden in the form )
          |
          C	= the detail



				Thanks,
					David.