It is very possible, but I will say that it is not going to be as easy to do using VBA as it is if you create an Add-In. For the most of it if you look at the API help under events you will find what you are looking for.
ApplicationEvents.OnSaveDocument
sample
In a new Class Module Named AppEvents add the following
Private WithEvents oAppEvents As ApplicationEvents
Public Sub Connect()
Set oAppEvents = ThisApplication.ApplicationEvents
End Sub
Public Sub disconnect()
Set oAppEvents = Nothing
End Sub
Private Sub oAppEvents_OnSaveDocument(ByVal DocumentObject As Document, ByVal BeforeOrAfter As EventTimingEnum, ByVal Context As NameValueMap, HandlingCode As HandlingCodeEnum)
If BeforeOrAfter = kAfter And DocumentObject.DocumentType = kPartDocumentObject Then ' this will happen after the save
' call your vba code
MsgBox ("you saved the part")
End If
End Sub
now in Module1 or another module of your choice add the following:
Option Explicit
Dim appevent As New AppEvents
Public Sub StartEvent()
appevent.Connect
End Sub
Public Sub StopEvent()
appevent.disconnect
End Sub
I hope before it will run you will have to call the StartEvent sub..