thanks Acetronics, i can deal with the more then 255 problem.

now another problem is that

how can i write

lookup a,[1,2,3,4,5,6,...........,255],b

in multiple line? and adding comment in the end of each line?

eg:
lookup a,[1,2,3,4,5,6,7,8,9,10, ; line 1
11,12,13,14,15, ; line 2
.................... ],b