MicroX Program/Combi select from an external controller

[techno-id]

Hello all !

I would like to set up my Novation SL 61 MK II so that I could change from its keyboard the sound of my MicroX. I could do that easily when I used my old CME UF5, I never had to set it up and it was working. (I decided to replace the UF5 because of constant problems with the MIDI clock but the brand new Novation does not have in preset option the change of the sound).
Yesterday, I made a template for my MicroX in the Novation, which allows me to change different parameters such as cutoff, frequency, etc. This one works . But now, about this program/combi changing control, I don't know how to do it. I don't understand exactly whether I have to send CC (Korg French technical assistance said no but could not help any further), RPN or NRPN to do that. I've tried many combination of these (following the booklet instruction from Korg) but it never gave me any result. What is the command to send ? What protocol should I follow ? I'm lost and hoping to getting some help ...

By the way I'm used to MIDI machines, connecting and usual stuff, but when it comes to the RPN and NRPN I'm lost in an awful nightmare

The MicroX is set up to receive any message in GLOBAL page.

[techno-id]

After another while of different manip, I finally could configure the Novation to change the sounds in a bank, so now one button makes me go to next sound, another button makes me go to the previous sound ... But ... these buttons are not synchronized to the MicroX so say I went to sound # 101 by increasing, if I use the decreasing button it won't bring be to # 100 but to the # before the one I was giong down previously (is that clear and even English ? God, help me I'm only a Frogg Eater !!)
This because there is no feed back from the Korg I guess, even if both machines are connected together in MIDI IN and OUT. And this is also because the 2 buttons I set up are not connected together, just 2 controls on their onw.
Should I use sysex ? I don't know either how to do this ...

I'm afraid this is all because of the Novation, which is not that easy to configure, and which can only accept setup for buttons and pads and not for rotary and faders.

Anybody here has an idea ? Knows a procedure ? Has been thru such a mess before ?