You can get panel mount IEC connectors: my approach here would probably be to either cut a hole in a blanking plate for a slot or to make a new blanking plate, make up an IEC extension cable with a panel mount connector on the far end (or try to find someone to make one for me for money), mount that panel mount connector on my modified blanking plate and call it a day.
This is really a case mod project rather than an electrical one: I'd suggest using a blanking plate to avoid irreversible mods to the case itself, because it's going to require a steady hand to make it look nice, I expect.