Just to clarify...
1. You have openelec installed, and are running libreelec from sd card?
2. Your remote works in openelec but not in libreelec?
3. When you run libreelec there's no remore.conf file in the configfiles share (/storage/.config/remote.conf).
If all 3 are a 'yes' then it should just be a case of pulling your sd card, booting openelec looking in the configfiles share for remote.conf and copying it to eg your pc, then running libreelec and pasting it in.
If all 3 aren't 'yes' then you need to clarify exactly what's on your box / what's on your sd card / what works / what doesn't.