Help needed: Calendar Control to DBGrid Field

I have a DB application that uses a Query to display selected rows in a
DBGrid. One of the fields is a date field. The date field has an elipsis
button set up and activates a second form with a calendar control.
Everything works fine except I can not get the result from the calendar
control on form 2 back into the DB Grid date field. I have tried:

frmGrid.Query2.Fields[1].AsTDateField := frmDate.Calendar1.Date;

and many other permutations of the above. What do I need to do to get the
date from the Calendar control (of DateTimePicker Control if that is better)
into the DBGrid field? This is easy in VB.

I am using Delphi4 Standard and a Access97DB. I have a memo form set up that
feeds a memo field on the grid and works just fine.