event equal to 1-200 do something
event equal to 201-400 do something else
say you're writing event 20.
20.- event equal to 1-200
+......
Event 20 would *always* fire. Thus it would be better to set it to "always"
Conversely, say you're writing event 201
201.- event equal to 1-200
+.....
Event 201 would *never* fire.
I hope I'm clear, such a condition would not useful at all. (also, as others said, it would be a nightmare to maintain). Try grouping instead, you can enable or disable whole event groups.