sorting strings having numbers..

Question

Hi.......
In my project i am using access database.in my table, 'Voucher No' field is of  text type.
so when i display the records from this table in the order of voucherno,it is not in the correct order like(1,,10,11,2,21,3)..as it is of string.so how can i make it in correct order with out changing the field type as number.because in some cases i need to save the voucher no as text.is there any way to do that...
reply me plz....