Okay so the Display is set when the form opens.
Lets set the names of this control to "DateDisplay"
In the Form_Open event put some code that sets the value. To do this :-
With Form in Design view click on the grey square, top left between the vertical and horizontal rules
Click on the Properties tool to display the Properties dialog box.
In the On_Open event double click in the space to the right - The words [Event Procedure] will appear.
Click on the small button on the right with three dots in it.
You are now in the On_Open event procedure.
Add code :-
Private Sub Form_Open()
DateDisplay = "Today's date is " & Format(Date,"Medium Date"

( or whatever value you want to appear in the box .. )
End Sub
Then back to the form.
Click on the User Entry Date Field ( Lets call it 'txtDate' )
In the After_Update event :-
Private Sub txtDate_AfterUpdate()
DateDisplay = "Today's date is " & Format(txtDate,"Medium Date"

( or whatever value you want to appear in the box .. )
End Sub
Then back to the form.
Click on the Combo box { I'm assuming that by a 'Drop down list box' you mean a combo box } ( Lets call it 'cboSelection' )
In the After_Update event :-
Private Sub cboSelection_AfterUpdate()
DateDisplay = "The updated Selection is " & cboSelection)
( or whatever value you want to appear in the box .. )
End Sub
I've put dummy text stings into the DateDisplay because you've not said exactly what the DateDisplay should contain.
With the above, if you change DateDisplay based on txtDate or cboSelection then it will remain showing that value when user moves to another record. Is that okay ?
If you need it to revert to the PC system date generated value then move the code from the Form's On_Open to the Form's On_Current event
'ope-that-'elps.
G LS