Statement.executeUpdate(String sql, int columnIndexes[]) via RETURNING clause?

Does anyone have knowledge of how to implement:

Statement.executeUpdate(String sql, int columnIndexes[])

This would be in the context of using the server's RETURNING clause. For
named-identifiers this is straightforward but I do not know how the
'returning' clause could support numbers... hopefully it can.

Something like?:

... RETURNING [1],[2]

Ken