Serial CANBUS addressing

Hi all-

I’m trying to make a arduino powered CANbus module (using the V1.3 serial CANbus shield) on an industrial automation network. I was able to get two modules to send and recieve to each other, but the spec for the industrial network has message IDs with an “h” at the end - (i.e. 045h, 200h, etc) - how do I format that? The examples are using an unsigned long variable for the ID…

I know… dumb question…