DECLARE
 fr_charset CONSTANT VARCHAR2(30) := 'WE8ISO8859P1';

 to_charset VARCHAR2(30) := 'WE8MSWIN1252';
 rawvar     RAW(100);
 v_rec      VARCHAR2(100);
BEGIN
  
  select x --value of x is chr(151)
    into v_rec
    from x;

  rawvar := utl_raw.convert(UTL_RAW.CAST_TO_RAW(v_rec),
  'AMERICAN_AMERICA.'||to_charset,
  'AMERICAN_AMERICA.'||fr_charset);

  dbms_output.put_line(utl_raw.cast_to_varchar2(rawvar));
  message('AMERICAN_AMERICA.'||fr_charset);
  message('AMERICAN_AMERICA.'||fr_charset);
  :text_item5:=utl_raw.cast_to_varchar2(rawvar);
END;