Crystal Reports Date Parameter Default Value OPtion Empty

Is there a way to set a default date value for a Date Parameter? It is shown empty, it only allows to set a fixed date, i.e. 10/10/2013. But it doesn´t allow me to use a formula (which has a CurrentDate inside), so I can set, for example, today's date as default.

How can I achieve this? I´m not using Crystal for Enterprise. I'm using Crystal Reports, the normal version.