The VX7000 has no IR eye. It is controlled via a Beovision with the remote signals being picked up by the TV and sent along the SCART cable. No Beovision, no remote control.
To change which remote works, first you need to make sure you have the correct VX7000! Early ones have a type number starting 45, later ones start 46. Only later ones work with the Beo4. I attach the instructions on how to switch remote types.