Maybe use the Form current event.
Code:
Private Sub Form_Current()
If Me.NewRecord Then
Me.DocketNumber = DMax("DocketNumber", "YourTableName") + 1 '<<< change YourTableName to the name of the table that holds DocketNumber
End If
End Sub
For the control, you might consider setting the Enabled property to False and the Locked property to TRUE.
BTW, DON'T use spaces in object names.
"Date" is a reserved word in Access and, by itself, not very descriptive. "Date" of What???? Birth date? Date of entry??