Change data type of a column

 I found out that one of our application code is doing a weird conversion from character to a date. This statement impacted the system a lot. I know that I can't just change the data type from varchar2(30) to a date by issuing  an alter statement. My question is that if I do an import/export of the table and re-create the table with the new date datatype. Will the data I exported with the old table with the old data type be able to inserted into the new table with the new datatype? How can I change the varchar2 to