This truly is off-topic, but in the spirit of the question ...

If you are trying to control a 7-segment type LCD screen with say two lines of ten 7-segment characters each, then you would first need a hardware driver for the LCD and then some way to talk to the driver. Usually, those drivers can be talked to through serial-type communication, where bits are shifted in with an external clock. Since your computer only knows about RS-232 serial ports, you'd have to rig up your hardware with some kind of a processor (like the PIC uC from Microchip) and then have this processor generate the clock and shift out the bits.

On the other hand, if you are talking about a larger dot matrix type LCD screen, then the drivers become much more complicated to control (I personally have never dealt with those). Likewise, if you are interested in driving a color LCD (like a 3"x5"), then the control is even more cumbersome, however, even that can be done with PICs (two actually because the horsepower of one is not enough for both Vsynch and HSynch).

As for remote control, well, you are off into another realm of problems. Digikey sells some RF transmitters/receivers that are fairly easy (relatively speaking) to implement with a PIC, but I'm not sure if those will be able to work over 30m.

Hope this helps.