You could run what’s called an Optical Character Recognition (OCR) program (one may have come with the scanner) on the scanned document and convert it to text that Word can handle, but OCR is an art, not a science. I can almost guarantee that you will have to fix:
1. Mis-converted fonts.
2. Mis-read characters (i for l, for instance, o, 0 or Q mixups)
3. Mangled layout.
The scanned document, as a Word file, may look nothing like the paper copy. Depending on the document’s layout, you might spend a lot of time getting it close to what the original looked like.
Hope that helps.