I have seen your capx, but i do not understand what you try to do.
So, let me tell you some basics.
Lets say we trow dices. Now the randomness depends on how much times you try.
So if you really want true randomness, the you got to try a lot. To do this in c2, try this.
Global variable 'timer' ... number .. = 0
Global variable 'Pick_Ups' .. number .. = 0
condition > system > every tick
action > system > set value ... variable = 'timer' ... value = floor(random(1,5))
action > system > set value ... variable = 'Pick_Ups' ... value = floor(random(4,31))
condition > system > every x second ... interval=timer
sub condition > system > compare two values ... 1st value = Pick_Ups .. = .. 2d value = 5
condition > system > once while true
action > create on random places