OCR Software for Handwritten numbers

I need to design an OCR software which recognizes (& learn) handwritten text in a standard sheet. The data to process is primarely numbers, with an excel layout. The software created should be expandible (in a future version) for the purpose of recognize 4 other sheet structures apart from the provided here. We work with 80 clients, or 80 different handwrittings: so, the "learning" function it's very important. About the program, It must have: 1) A queue for reading and processing. 2) It should "ask" when a code or number it's not recognizable. Please, first read "Sheet structure" and "About Shift and LotCodes" to understand the layout.