HCELL_INDEX
CmpDoFindSubKeyByNumber(
      PHHIVE Hive,
      PCM_KEY_INDEX Index,
      ULONG Number
  );

Routine Description:

    Helper for CmpFindSubKeyByNumber,
    Find the Number'th entry in the index, starting from 0.

Arguments:

    Hive - pointer to hive control structure for hive of interest

    Index - root or leaf of the index

    Number - ordinal of child key to return

Return Value:

    Cell of requested entry. HCELL_NIL on resources problem