Note: Add a reference in your project to PDFmergeNET To do this:    a. On the Project menu, click Add Reference;    b. On the .NET tab, locate PDFmergeNET and then click Select;    c. Click OK in the Add References dialog box to accept your selections.

          PDFsplit.Neevia NVsplit = new PDFsplit.Neevia();
          int retVal;
          // Extract pages 2,3,7
          retVal = NVsplit.SplitPDF(@"c:\1.pdf(2,3,7)", @"c:\out\");
          if (retVal != 0)
          {
              MessageBox.Show("Error code = " + retVal.ToString());
          }
          else
          {
              MessageBox.Show("Done");
          }