I did a similar setup. The back side of LCDs are shinny I noticed but dont effect or interfere with any IR. You can point any remote control to your LCD and click some buttons and see the results through your camera. You will notice that IR from remote will pass through just fine.
And as Vlado mentioned, you need to put an Acrylic sheet infront of the LCD, thats where the magic happens, ofcourse with IR LEDs on all or couple of sides. Also make sure that your camera is modded before you start testing it fully.