use lcd with DE-2

Writing code to do something in Verilog would be a module. Using it elsewhere would be using that module. It's the same thing as a core.

Have a look here: http://www.altera.com/education/univ/materials/comp_org/ip-cores/unv-ip-cores.html

They have a library for the LCD but you need to use NIOS-II to use it.