Hello again,
well i'm struggling for several months now with this mce remote and xbmc but today i found a very awesome site taking care of this topic. You can get a predefined keyboard.xml there. The downloaded xml file combined with the xbmc plugin for mceremotes where you can edit this file with a specific editor resolved all my problems with this remote. Finally i can use it like i want.
So here's a summary what you need to customize your keypresses:
- keyboard.xml (please check the site for more infos)
- mceremote add-on (install it from the add-on page in xbmc, after installation it can be found under "programs")
I hope this helps someone.