Remote control of hidden components?

How do I control my gear with remote if it's hidden behind cabinet doors? HT novice so be kind.

Is there a device that plugs into the rear of the BDP, Receiver,... (isn't there an IR plug on the back?) and another part sits on top of cabinet? Something simple, not expensive. Then there's the four remotes I have also. There has to be an inexpensive solution for this without getting too complicated and messy.

Thanks