Public Function ObtieneListIndex(unCombo As ComboBox, pItemData As Long) As Integer
Dim i As Integer
For i = 0 To unCombo.ListCount - 1
    If pItemData = unCombo.ItemData(i) Then
        ObtieneListIndex = i
        Exit Function
    End If
Next
ObtieneListIndex = -1
End Function

Dim da As New OleDb.OleDbDataAdapter(STRSQL, CN)
        'Dim da As New OleDbDataAdapter(STRSQL, conexion)
        Dim ds As New DataTable(Tabla)
        '  Conexion.Open()
        da.Fill(ds)
        With CMB
            CMB.DisplayMember = Campo
            CMB.ValueMember = Indice
            CMB.DataSource = ds
            CMB.Text = " "
        End With

        Public Function Obtiene_ListIndex(ByVal UnCOmbo As ComboBox, ByVal pItemdata As Integer) As Integer

        Dim I As Integer

        For I = 0 To UnCOmbo.Items.Count
            If pItemdata = UnCOmbo.Items.IndexOf(I) Then
                Obtiene_ListIndex = I
            End If
        Next
    End Function