I haven't done much with direct entry of RC6A codes in ProntoEdit. Lyndel's instructions look plausible and I assume they are correct.

But the linked HP documentation only shows that one combination of Customer Code and System code, that fits the list of signals they call "Entertainment group 1". They have a second list of signals called "Entertainment group 2" without telling you a different Customer Code or System code.

If I'm reading the binary right and if I correctly understand what "System code" means in ProntoEdit, then the second list uses the same Customer Code as the first, but System Code 18 instead of 2.

My software (DecodeIR and MakeHex, etc.) call this protocol "MCE". If you want to generate ordinary Pronto Hex with MakeHex, use MCE.irp and set device=2.17 for "Entertainment group 1" and rerun with device=18.17 for "Entertainment group 2". In both cases the "Code Number" in the HP document is the function number in the MakeHex output.