I am working with crystal report and i need to change the date format, i can't do it with the tabs because the date is in string, what is the sytax to change it?

{calllog.callstatus} = "Open" and
{Calllog.Priority} = "1" and
{Asgnmnt.Dateassign} <= &#34;2000-5-17

and i want to change the date to mm-dd-yy

Thanks