vb6 to update a sharepoint calendar

currently I have a vb6 program that inputs events(vacations) into your outlook calendar. How can I now reconfigure it to update a sharepoint calendar? thanks. This is what I currently have:

Private Sub addToCalendar()

' Start Outlook.
Dim olApp As Outlook.Application
Set olApp = CreateObject("Outlook.Application")

' Logon. Dim olNs As Outlook.NameSpace
Set olNs = olApp.GetNamespace("MAPI")
olNs.logon

' Create a new appointment.
Dim olAppt As Outlook.AppointmentItem
Set olAppt = olApp.CreateItem(olAppointmentItem)

' Setup other appointment information...
With olAppt
.Subject = "on holidays."
.ReminderSet = False
.Start = txtStartDt.Text
.End = txtEndDt.Text
.AllDayEvent = True

End With
' Save Appointment...
olAppt.Save

End Sub