What about with bar code in documents (read & write), find by number or with laser reader bar code (like in super market)?
It can be done, but it's not a job that directly does DMS.
The idea is get some OCR, scanning and extract that information -> then uploading document and information as metadata ( you can search by metadata ).
There're some cheap OCR that can do it ... we're finishing to closing some collaboration with Omnipage Pro ( I can recommend it ).