[DXCategory("Events")]
public event LookUpEditAutoSearchEventHandler AutoSearch

<DXCategory("Events")>
Public Event AutoSearch As LookUpEditAutoSearchEventHandler

lookUpEdit1.AutoSearch += OnAutoSearch;

void OnAutoSearch(object sender, LookUpEditAutoSearchEventArgs e) {
    string[] fields = new string[] { "ShipCity", "ShipCountry" };
    e.SetParameters(fields, e.Text, FindPanelParserKind.And, FilterCondition.StartsWith);
}

Private lookUpEdit1.AutoSearch += AddressOf OnAutoSearch

Private Sub OnAutoSearch(ByVal sender As Object, ByVal e As LookUpEditAutoSearchEventArgs)
    Dim fields() As String = { "ShipCity", "ShipCountry" }
    e.SetParameters(fields, e.Text, FindPanelParserKind.And, FilterCondition.StartsWith)
End Sub

private void LookUpEdit1_AutoSearch(object sender, LookUpEditAutoSearchEventArgs e)
{
    e.SetParameters(FindPanelParserKind.And, FilterCondition.StartsWith);
    e.SetHighlightRanges(CustomHightlight(e.Text));
}

static Func<string, string, DisplayTextHighlightRange[]> CustomHightlight(string userText)
{
    return (displayText, fieldName) =>
    {
        if (fieldName == "ShipCity" || fieldName == "ShipCountry")
        {
            if (displayText.StartsWith(userText))
                return new DisplayTextHighlightRange[] {
                    new DisplayTextHighlightRange(0, displayText.Length) };
        }
        return null;
    };
}

Private Sub LookUpEdit1_AutoSearch(ByVal sender As Object, ByVal e As LookUpEditAutoSearchEventArgs)
    e.SetParameters(FindPanelParserKind.And, FilterCondition.StartsWith)
    e.SetHighlightRanges(CustomHightlight(e.Text))
End Sub

Shared Function CustomHightlight(ByVal userText As String) As Func(Of String, String, DisplayTextHighlightRange())
    Return Function(displayText, fieldName)
        If fieldName = "ShipCity" OrElse fieldName = "ShipCountry" Then
            If displayText.StartsWith(userText) Then
                Return New DisplayTextHighlightRange() { New DisplayTextHighlightRange(0, displayText.Length) }
            End If
        End If
        Return Nothing
    End Function
End Function