Handwriting on scanned documents are, at the best, not done very well. You
will need a special program that can recognize the handwriting in the
scanned document. IIRC word 2002 (XP) does not have this feature for
scanned documents. The program that came with a tablet I have can recognize
my sloppy handwriting but it won't convert a scanned document.
Microsoft's support seems to be limited to input from a device not a file.
http://support.microsoft.com/kb/306906/
Do a Google search for handwriting recognition.