Have you checked that your IR receiver doesn't have an external IR jack?
It's not that unusual for consumer audio gear, projectors etc. to have the capability for an external IR receiver that is in the line of sight of the remote, say, by the TV.
If there is no existing facility, most IR receiver modules have open-collector outputs, so it would be relatively easy to arrange an external one in parallel with the internal one using a thin three core lead (eg, two core stereo screened).
You would probably want to check the internal IR receiver part number for modulation frequency (usually 36-38kHz) and get the same.
Note the usual warning about modifying mains powered equipment, but if you were already contemplating a wired link then you have probably already accepted that.