I presume you would want backup running thru that card.
Do as Corona mentioned, configure a separate subnet, define an address and add a route. Define in it in netconf for persistence across reboots.
If you want to create an aggregation of those two interfaces, it is called on HPUX - APA (Auto port aggregation).
You will need to read the documentation about it which is here :
HP-UX Auto Port Aggregation (APA) Software- Manuals - HP Business Support Center
Choose your method according to your needs, be sure to check hardware requirements and configure your network accordingly.