Private void Form1_Load(object sender, System.EventArgs e)
{
    rptInsertPage rpt = New rptInsertPage();
    viewer1.Document = rpt.Document;
    rpt.Run();
    rpt.Document.Pages.InsertNew(3);
}

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim rpt As New rptInsertPage()
    Viewer1.Document = rpt.Document    rpt.Run()
    rpt.Document.Pages.InsertNew(3)
End Sub