You need to separate you problem into two pieces: how to program the LCD, and how to do it using BASCOM.

Progress can be made on the first step by going through the tutorial here regarding programming LCDs. Then you will want to double check your particular LCD datasheet to confirm that the example code will actually apply to it...there are different LCD controllers, so you might have to make some adjustments.

I haven't used Bascom, so I'm afraid I can't be of much help there, but surely your compiler/interpreter came with some documentation regarding its use?

Dennis