Stamp pdf at specific position

HI,
I need to stamp different pdfs received from external parties. So the sizes, orientation, layers and applications that generated the pdf differs.
I have control over the PDF stamp size. Let say Aspose.Pdf.Stamp.Height 50 x Aspose.Pdf.Stamp.Width 50.
I want to be able to specify exactly where the stamp must be.

Bottom Left is easy
Indenting from the side 10 and 10 from bottom:
pageStamp.YIndent = 0 + 10 and pageStamp.XIndent = 0 + 10

Top right is not so simple. I don’t know from where to start and deduct 10 for X and Y
Should I and when should I use pdfpage.PageInfo.Height or pdfpage.CropBox.Height.

So how do I calculate where to put a stamp of 50 x 50 at a position 10 from the top and 10 from the side. Snugly in the top right hand corner of any pdf, orientation and size?

@miguels

You can get different properties of page using the API and add the stamp as per your requirements using the API. However, if you are facing some issue, please share some sample PDF document along with information of your expected results so that we can test the scenario in our environment and address it accordingly.