Hi sabiqi,
LabVIEW comes with an OCR example that should be a good starting point for you. The OCR example doesn't do exactly what you are looking for but you can combine a few VIs to get exactly what you want. You can find the OCR example in the Example Finder (Help>>Find examples...) at this location:
Toolkits and Modules>>Vision>>Applications>>OCR Example.vi
Jaidev
Senior Product Manager
National Instruments