In that case it should be the same size, it's just a case of if it fits. It wouldn't be uncommon for the same part to be fitted to 2 different cars using different part numbers. I understand the confusion though.
Quick Google search shows the scenic part is 22mm which is thicker than the 200 cup part (21mm I believe), so measuring it will tell you what you have.
I have a broken front coil spring and reading posts like this really reminds me just how much I can't be arsed doing it myself (I will though, eventually)...
Try putting the window all the way down then holding the button for 10 seconds (I think it's 10 anyway). Then put the window all the way up and hold for 10 seconds. Try that a few times, and if that doesn't work lube the mechanism and/or the rubbers which run along the bottom of the window frame.
If I'm understanding correctly, you can buy a used ecu from a 197 and send it and your current ecu to someone who can swap the immobiliser over from the current ecu to your 'new' ecu. You'll then have a standard unlocked ecu which can be remapped.