declare
 type TOPERATTRS is TABLE of VARCHAR2(4000) not null INDEX BY VARCHAR2(30);
 cOperAttrs TOPERATTRS;
 s varchar2(100);
 function GetWord(p_pos int,p_s varchar2,p_r varchar2) return varchar2
 is
 begin
   return to_char(to_date(substr(p_s, instr(p_s,p_r,1,p_pos)+1, instr(p_s,p_r,1,p_pos+1)-instr(p_s,p_r,1,p_pos)-1),'yyyy'),'year');
 end;
begin
 s:='=1=2=3=';
 cOperAttrs(GetWord(1, s, '=')) := s;
 dbms_output.put_line(GetWord(2, s, '=')||' ->'||cOperAttrs(GetWord(1, s, '=')) );
end;
/
SQL> /
two ->=1=2=3=

PL/SQL procedure successfully completed.