How to integrate scanner device to read barcode with line identifier

There is a requirement to input data from a scanner to oracle form by using barcode. The advance requirement is, to identifier field name in barcode,which they call line identifier. When scan barcode the value will go to the field indentified in barcode. For example barcode is "@-Q-5200@", the value 5200 is shown to field name "Transaction Quantity" or "@-item-AS54888@", the value AS5488 is shown to field name "item". Could anyone give me a hint to perform customization Oracle Form to meet this requirement.