If you want to select a certain patch on the Roland JDXI or BK5, you have to work with MSB and LSB for the bank, and then select a program change. In Cubase, you can only enter one value for the bank, so how to calculate?
For the BK5, you take a look at the tone list in the manual. every sound has a CC00, CC32 and PC. The CC00 and CC32 make up the bank, while PC is the program. The value you have to enter in Cubase for the bank is calculated as CC00*128+CC32. So, if you want to select sound 607 (bottle blow 2), you'll see the values 47 and 4 for CC00 and CC32, and 77 as program change. These values are in decimal, so calculate 47*128, add 4, and that number (6148) your bank. Put this in the bankselecter, and 77 in the program selector, and there you have it: a BottleBlow2.
For the JDXI, it's kind of the same, but it differentiates between superNatural Synth tones, Analog Synt Tones and Drumkits. First, the SuperNatural Synt tones can only be used at MIDIchannels 1 and 2, the Analog Synth tones are at MIDI channel 3, drums are (as always) on MIDI channel 10.
On the JDXI itself, the sounds go from 1 to 277, 1 being JP8 string1, 277 being Voice In. It seems like the vocoder program changes cannot be selected using MIDI (or at least, the MIDI monitor isn't showing it (MIDI-OX, great little program, btw)). so the patches go from 1 to 245 (which is, probably not accidentally, almost two full banks of 128 patches). Drums go from 1 to 33, analog synth tones from 1 to 63.
Although MIDI uses 0 to 127 for program changes, Cubase uses 1 to 128, and 0 as off.
If you want the change the program, for the supernatural tones. program changes run from 1 to 128. the MSB is 95, LSB is 64, so 95*128+64 (12224) is the bankselector. For the other notes, substract 128 (so the range starts at 1), and that will be your program change. MSB again is 95, LSB is 65, so that would become 95*128+65 (12225) for the bank select. Be aware that this probably only works in MIDI channels 1 and 2.
Example: If you want to use patch 196 (Syn Vox 1), substract 128, which results in 68. As it is in the range from 128, use 12225 for the bank select, and 68 as program change. If you want to use patch 083, the program change is 83, and the bank select is 12224
For the drums on MIDI channel 10, it's basically the same. MSB is 86, LSB is 64, and program changes range from 1 to 33 (0 is not used). Bank select is 86*128+64, which is 11072. So, if you want to use House Kit 1 (program 10), use 11072 as bankselect, and 10 as program select.
And it is the same for the analog synth, which are on MIDI channel 3. MSB is 94, LSB is 64, so the bank select is 12096. program changes run from 1 to 64, so that's your program change.