Those kind of LCDs, just the glass, can either be very hard or very easy. I think what john1 was getting at is that large displays (with many segments) are kind of multiplexed. Not in the usual sense, it has to do with planes and duty cycles and complex controls and voltages. If you're extremely lucky, you might find one that has each segment brought out to a pin, then all you have to do is figure out which is which and apply a suitable voltage at an appropriate frequency, which is not critical.
Best bet, buy a cheap alphanumeric display with an onboard controller. They're like $3 or $4, less than you would pay for all the glue logic between your pic and the glass.
j.