Crystal Reports Ordering dates previously converted to string

Message

   I had to convert a date into string in order to use the value in a if-then statement
if {?group} = 0 then ToText(Date{DateTimeValue}), "MM-dd-yyyy")
else if {?grou} = 1 then {someStringValue}
else {someOtherStringValue};

If i pick 0 (zero) i need to group the report by DATE DESCENDING but having to deal with a string, the dates are not ordered properly (** see example below)

01-09-2012
01-20-2012
02-05-2012
03-01-2011**

Is there a workaround that i could use?

Thanks

Rick