If it is to just print on the card you can follow the steps below:
1 - Add a variable in the Card Designer called hexstring and map it to the source (eg.. database column)
2 - Add a text object to the card, in the content tab choose script and enter int(hexstring, 16)
Now the converted string should show on the card.
Hope that helps,
CardExchange Solutions Support Team
"If you define the problem correctly, you almost have the solution." (Steve Jobs)