Sort decimal data in an varchar2 field

Hello,

i have designed a table which contains varchar2 fields.

one of these fields contains decimal data.

i want to sort this table with this field using the caracteristics of the decimal data, not the string caracteristics because the sort order is not the same.

i intend to use the function TO_NUMBER(a,b) but i do not know how to use the 'b' statement to set up decimal caracteristics.

Could anybody help me ?

Thanks in advance.

best regards.

try it without parameter b or
for "b" put max value of "a".
example
SELECT To_Number('12.34567','99.99999') FROM dual;