Probably not that hard really. Problem is exactly what "the manufacturer" meant by his numbers like "0xff00 0xba45 - menu". Lets do some "intelligent" guessing:

The NEC protocol(s) take 32 bits, and you have 32 bits, fine. Note that byte 2 always appear to be the complement of byte 1, and byte 4 the complement of byte 3, again fine. So get IrScrutinizer and try it out, for generating the hex codes, and, given suitable hardware, shooting it at your equipment. For a first try, try the first byte (0xff = 255) for D, and the third byte (0xba = 186 for menu) for F. If that does not work, try to reverse the bit order (0x5D for menu), and/or complement them.