How can we add numbers to sub-assemblies in CATIA to see them in balloons and bom list automatically in drawing?

This is somewhat related, but I'm not using numbers for the BOM. Instead I'm trying to use balloons to label the top level assemblies AND parts directly. The auto balloon and balloon tool will only pick-up the part names, not the sub-assembly name so I have to annotate these with leaders instead of balloons. Any ideas? Here is what I'm trying to accomplish:

  1. Step 1:

    Axo with balloon annotation

  2. Step 2:

    BOM with Parts and Assemblies