I open a pdf file when my form is loaded with the following code:
Process process = new Process();
ProcessStartInfo startInfo = new ProcessStartInfo();
process.StartInfo = startInfo;
startInfo.FileName = @"F:\STAGE\test.pdf";
process.Start();
Try
process.StartInfo.Arguments = "/A \"page=n\" \"F:\\STAGE\\test.pdf"";
changing n
to the page number you want