Zebra printer issue -- 2

Hello there, We have a customer with 2 older printers GX430T/scanners LS2208. We need to first get a solution for those 2 devices. Then we need to create a solution based on the newer ZD series and scanners. We're thinking this would be 2 projects. As I understand it the difficulty is the check digit. In addition to duplicating the barcode itself we need to calculate a check digit based on the barcode contents and print it on the label. To be clear this check digit is NOT part of the barcode itself. For this project we're looking to be able to 'install' the solution on the 2 customer devices. We've been able to extract some files from a working solution made by a competitor. Those files will be attached to another message. I'll also include a program for verifying the check digit and VB and C source code. Files are attached. The first phase of this project will contain a GX430T printer and a LS2208 scanner connected to the printer. The customer will scan a barcode label and the printer will print an exact duplicate. 2. The customer will scan an existing label and the printer will print a copy. The label is 1.75 inches x 0.75 inches. 3. The ZPL I sent was extracted from a working solution. We believe this ZPL created the label. 4. I’m not sure what you mean by the barcode operation. The barcode is Code 128. The attached example scans as =W11512105657526 * The H on the label is the check digit I sent the code for. It must somehow be calculated and printed on the label. Let’s call the barcode being duplicated the original barcode. The original barcode was printed by another process. This solution does not have to create the original. All this solution has to do is duplicate the original. The customer will take the original barcode, using the GX430T and LS2208 hardware, scan the label and the software will print it on the GX430T. It has to be a standalone solution using only the printer and scanner. The printer will not be connected to any computer or network. Thanks