Barcode Scanning - Tracking people who attend events

I have done a lot of research on Barcode stuffs in excel, but have not found exactly what I am looking for... and not sure if it is possible.

Back story:
I volunteer at a Low Income facility that runs a Thanksgiving / Christmas / Easter / Back to School event for needy families. I am going to be overhauling their current database and how they log clients. Every client gets a 3x5 card with specific info on it that is turned in at each event. One of the biggest issues that they have is people trying to copy the cards to alter the info and then obtain more stuff.

If I print a barcode on each of these cards (barcode, QR code, etc), then it will have info that they cannot duplicate/remove hidden in that code..... but is there a way for me to scan the code and have it link back to the excel sheet so that I will know whose card was scanned?