C++ (Scan, identify & recognize PDF's)

Adding to an existing Programm written in C++ we need a new function. The existing programm is listing all PDF from a Windwos Folder, showing it and listing some details like "Name", "Date", "Amout" etc. At this moment every PDF must be reed and then fuled up every detail manually. We need a new "function" which will "scann" the document and recognize what sort of document it is and then via OCR reed some details and fill it in some input fields.