Active POR en VB contra un servidor

Te envío el código necesario para resolver tu necesidad, realiza una prueba y compleméntalo de acuerdo a tu caso específico.
Option Explicit
Private Sub form_load()
Com.CommPort = 1
Com.Settings = "9600,N,8,1"
Com.PortOpen = True
End Sub
Private Static Sub Com_OnComm()
Dim bufferin As String
Dim datos As String
Dim exten As String
Dim trunk As String
Dim fecha As String
Dim fec As String
Dim tinic As String
Dim durac As String
Dim descr As String
Dim numfil As Integer
Com.RThreshold = 0
If Com.CommEvent = comEvReceive Then
Com.InputLen = 0
If Com.InBufferCount Then
bufferin = Com.Input
datos = bufferin
Text1.Text = Text1.Text & bufferin
exten = Mid(datos, 4, 3)
trunk = Mid(datos, 11, 3)
fec = Mid(datos, 18, 5)
fec = Replace(fec, ":", "/")
fecha = fec & Mid(Date, 6, 3)
tinic = Mid(datos, 26, 8)
durac = Mid(datos, 37, 8)
descr = Mid(datos, 48, 8)
Text2.Text = exten & Chr(32) & trunk & Chr(32) & fecha & Chr(32) & tinic & Chr(32) & durac & Chr(32) & descr
numfil = FreeFile
Open "C:\PruebaLLamadas.txt" For Append As #numfil
Write #numfil, exten & Chr(32) & trunk & Chr(32) & fecha & Chr(32) & tinic & Chr(32) & durac & Chr(32) & descr
Close #numfil
End If
Com.RThreshold = 1
Else
MsgBox "Error o suceso desconocido"
End If
End Sub