scott@test>desc test
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------

 X                                                  VARCHAR2(10)

scott@test>select * from test;

X
----------
1
100
2
9
999
alum
brass

scott@test>select x from test order by lpad(x,10,' ');

X
----------
1
2
9
100
999
alum
brass

7 rows selected.

scott@test>insert into test values('200');

1 row created.

scott@test>select x from test order by lpad(x,10,' ');

X
----------
1
2
9
100
200
999
alum
brass

8 rows selected.

scott@test>