The way to do that is, assuming the random number rolled will be the variable applied to the sprite:
Using events simply make multiple conditions stating the range you want to use.
IE (pseudo code)
(condition)
Sprite1.variable "roll" equals 1
Sprite1.variable "roll" equals 2
Sprite1.variable "roll" equals 3
(event)
Do stuff
-----
(condition)
Sprite1.variable "roll" equals 4
Sprite1.variable "roll" equals 5
(event)
Do different stuff
-----
(condition)
Sprite1.variable "roll" equals 6
(event)
Do some more different stuff
So basically you change the variable of the sprite itself (randomly) to match a list of pre-determined conditions.
~Sol