Parsing string in PL/SQL stored procedure

You can iterate by occurences regexp_substr, or just select them like this

for item in (SELECT regexp_substr('1200-abc,1300,1400-enhk1,1500', '\w(\d+)\w', 1, LEVEL) val
      FROM dual
    CONNECT BY regexp_substr('1200-abc,1300,1400-enhk1,1500', '\w(\d+)\w', 1, LEVEL) IS NOT NULL)
loop
      dbms_output.put_line(item.val);
end loop;

You can make like this :

declare

  i varchar2(4000);
  v_array apex_application_global.vc_arr2;
  only_numbers  varchar2(100) :='';
begin

  i := '1200-abc,1300,1400-enhk1,1500';

  v_array := apex_util.string_to_table(i, ',');

  for e in 1 .. v_array.count loop

      only_numbers:=only_numbers || regexp_substr(v_array(e),'[[:digit:]]*') ||',';


  end loop;

only_numbers := rtrim( only_numbers, ',' );
dbms_output.put_line(only_numbers);   -- output :  1200,1300,1400,1500

end;

create function del_non_numerics(str varchar2)
return varchar2
is
v_return_txt varchar2(3000);
begin
select regexp_replace(str,'[^0-9,]+','') into v_return_txt
from dual;

return v_return_txt;
end;
/

Invoking the above code as del_non_numerics('1200-abc,1300,1400-enhkl,1500') => 1200,1300,1400,1500