To expand on Corion's answer, if your HP product provides an OLE interface, you can use Win32::OLE as seen these examples. However, to know the OLE interface, you need to have documentation from your vendor.

If there is no OLE interface at all, perhaps because HP didn't ever intend outside programs/scripts/applications from communicating with the sofware, you can use Win32::GuiTest to directly manipulate the interface elements in an automated fashion.

UPDATE: In trying to see if there is any way of getting OLE information without documentation, I came across a Stack Overflow OLE Automation Question. See the comment from 1800 INFORMATION.