You can use your own print dialog:

PrintDialog dlg = new PrintDialog();
dlg.Document = new PrintDocument();
dlg.Document.PrinterSettings.FromPage = 1;
dlg.Document.PrinterSettings.ToPage = 100;
if (dlg.ShowDialog(this) == DialogResult.OK)
     fc.Print(dlg.Document);

I hope that helps,
Stoyan

Set docRect = FlowChart.GetContentRect(true, true) to find out the size of the printable area. The A4 paper size is 210 mm by 297 mm. Subtract the margin size from the paper size and assign the result to pageRect. Make sure all values used in the calculation are measured in the same unit. Finally

int xPages = (int)Math.Ceiling(docRect.Width / pageRect.Width);
int yPages = (int)Math.Ceiling(docRect.Height / pageRect.Height);

The last page number is xPages * yPages.

I hope that helps,
Stoyan