VARIABLENAME:= 'Select a from abc';
declare cursor for VARIABLENAME

DECLARE
  TYPE ty_rc IS REF CURSOR;

  c      ty_rc;
  v_date date;
BEGIN
  OPEN c FOR 'select sysdate from dual';
  FETCH c INTO v_date;
  CLOSE c;
END;
/

SQL> DECLARE
  2    TYPE ty_rc IS REF CURSOR;
  3    c      ty_rc;
  4    v_month VARCHAR2 (15);
  5    str VARCHAR2(50):='select TO_CHAR(sysdate,''MONTH'') from dual';
  6  BEGIN
  7    OPEN c FOR str;
  8    FETCH c INTO v_month;
  9    DBMS_OUTPUT.PUT_LINE('MONTH is :'||v_month);
 10    CLOSE c;
 11  END;
 12  /
MONTH is :NOVEMBER

PL/SQL procedure successfully completed.

SQL>