I'm able to send a single appointment from inside Access to Outlook.
This is the core code:
With OutAppt
.Subject = [Nominativo_Paziente]
.Start = [DataInizio] & " " & [OraInizio]
.End = [DataFine] & " " & [OraFine]
.FormDescription = [DescrizioniVarie]
.Location = [Nominativo_Medico]
.ReminderSet = False
.Save
End With

How can I tell him to "Replace duplicates with items imported"?

Bruno