In 9i, you can use :

ROWID_BLOCK_NUMBER Function
This function returns the database block number for the input ROWID.

Syntax
DBMS_ROWID.ROWID_BLOCK_NUMBER (
row_id IN ROWID)
RETURN NUMBER;

Pragmas
pragma RESTRICT_REFERENCES(rowid_block_number,WNDS,RNDS,WNPS,RNPS);

Parameters
Table 62-7 ROWID_BLOCK_NUMBER Function Parameters
Parameter Description
row_id
ROWID to be interpreted.


Example
The example SQL statement selects the block number from a ROWID and inserts it into another table:

INSERT INTO T2 (SELECT dbms_rowid.rowid_block_number(ROWID)
FROM some_table
WHERE key_value = 42);