DateTimePicker and dataset

I've read many web pages and messages in newsgroups talking about this
issue, but I haven't found a solution to my problem.
I need to have a datetimepicker control bound to a dataset (an Access file).
The problem comes out when I want to add a new record: the user needs to
pick a date from the datetimepicker control, otherwise a null value (and not
the default value / text of the control) is written in the database.
What I need is some way to make my program understand that it needs to write
dtp's text / value into the database even if the user doesn't touch that
control.
Any solution to this?

Thanks in advance,
G