how to use ComboBox dropdownlist searching in string not just the first lettercharacter in vb.net

Dear Sir 

I'm Trying to use ComboBox dropdownlist searching in string not just the first letter/character in vb.net

so I can type 3 characters or 4 characters

Please Guide Me.

Thanks

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        InitializeComboBox()
    End Sub
    Private Sub InitializeComboBox()
        Dim employees() As String = New String() {"Hamilton, David",
            "Hensien, Kari", "Hammond, Maria", "Harris, Keith",
            "Henshaw, Jeff D.", "Hanson, Mark", "Harnpadoungsataya, Sariya",
            "Harrington, Mark", "Harris, Keith", "Hartwig, Doris",
            "Harui, Roger", "Hassall, Mark", "Hasselberg, Jonas",
            "Harnpadoungsataya, Sariya", "Henshaw, Jeff D.", "Henshaw, Jeff D.",
            "Hensien, Kari", "Harris, Keith", "Henshaw, Jeff D.",
            "Hensien, Kari", "Hasselberg, Jonas", "Harrington, Mark",
            "Hedlund, Magnus", "Hay, Jeff", "Heidepriem, Brandon D."}
        ComboBox1.Items.AddRange(employees)
        Me.ComboBox1.IntegralHeight = False
        Me.ComboBox1.MaxDropDownItems = 5
        Me.ComboBox1.DropDownStyle = ComboBoxStyle.DropDownList
        Me.ComboBox1.TabIndex = 0
    End Sub
End Class