You can add an alarm to a single appointment by setting the necessary properties, as shown in the following sample code:
objItem.SetProperties AlarmTypeUnit:=0, AlarmAmount:=15, Ring:=TRUE
For tasks, the following sample code shows how the BeforeEnd property can be used to indicate that the alarm should ring before the end of the item:
objItem.SetProperties , _
AlarmTypeUnit:=0, AlarmAmount:=15, _
Ring:=True, BeforeEnd:=True