Code:
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> create table t1 (c1 varchar2(8));

Table created.

SQL> insert into t1 values ('010190');

1 row created.

SQL> insert into t1 values ('010290');

1 row created.

SQL> commit;

Commit complete.

SQL> select * from t1 where to_date(c1,'MMDDYY') >= to_date('010190','MMDDYY');

C1
--------
010190
010290

SQL>