How to change the orientation of signature object according to the Page Rotation

Hello,

I have developed one component in VC++ which Signs PDF files.

I have some PDF files in which pages are rotated in  90 or 180 or 270 degrees.When I sign a PDF file with page orientation as "/Rotate 90" then signature annotation is coming as vertical but when I sign same PDF file using Adobe Pro 9 then it is coming as horizontal (Please see the attached screen shot for your reference).

What do I do so that signature annotations will also get rotated according to page orientation?

Thanks and Regards,

Priyanka