Updating Contact Info In Outlook

I have the following code working great with creating new contacts in Outlook from Access. My problem is I can't figure out a way to update already existing contacts in Outlook.

Function AddContacts()

Dim OutlookObj As Outlook.Application
Dim Nms As Outlook.NameSpace
Dim MyContacts As Object
Dim MyItems As Object
Dim MyItem As Object
Dim Db As Database
Dim Rst As Recordset

Set Db = CurrentDb
Set Rst = Db.OpenRecordset("CustomerOutlook", dbOpenDynaset)
Set OutlookObj = CreateObject("Outlook.application")
Set Nms = OutlookObj.GetNamespace("MAPI")

'to point to a nested folder in Outlook you have to create folder items in folder items:
Set MyContacts = Nms.Folders.Item("Public Folders").Folders.Item("All Public Folders").Folders.Item("Our Contacts")
Set MyItems = MyContacts.Items

While Not Rst.EOF
'Declare which form to be used to add your contacts
Set MyItem = MyItems.Add("IPM.Contact")

'add fields, to find out which fields are available take a look at all the available members of the
'ContactItem class in the Outlook object library.
'Be careful, Microsoft is using various names for outlook fields!
MyItem.CompanyName = Rst!BusinessName
MyItem.FirstName = Rst!CFirst
MyItem.LastName = Rst!CLast
If Not IsNothing(Me.WebSite) Then
MyItem.WebPage = Rst!WebSite
End If
If Not IsNothing(Me.CMiddle) Then
MyItem.MiddleName = Rst!CMiddle
End If
If Not IsNothing(Me.Suffix) Then
MyItem.Suffix = Rst!Suffix
End If
MyItem.JobTitle = Rst!JobTitle
MyItem.BusinessTelephoneNumber = Rst!Phone
MyItem.Business2TelephoneNumber = Rst!BackPhone
MyItem.MobileTelephoneNumber = Rst!Mobile
MyItem.BusinessFaxNumber = Rst!Fax
MyItem.Email1Address = Rst!Email
If Not IsNothing(Me.Address1) Then
If Not IsNothing(Me.Address2) Then
MyItem.BusinessAddressStreet = Rst!Address1 & ", " & Rst!Address2
Else
MyItem.BusinessAddressStreet = Rst!Address1
End If
End If
MyItem.BusinessAddressCity = Rst!CCity
MyItem.BusinessAddressState = Rst!CState
MyItem.BusinessAddressPostalCode = Rst!PostalCode
MyItem.Categories = Rst!CustomerType
MyItem.FileAs = Rst!BusinessName

'MyItem.Etc = Rst!Etc
MyItem.Close (olSave)
Rst.MoveNext
Wend
End Function