Basically, it takes the input value and subtracts the users lowest value to use as the low range limit and adds the users highest value for the users high range limit:
user inputs
Input float = 2
min range = 1
max range =1
min range subtracted from input = 1
max range added to input = 3
random range between min & max (between 1 & 3)
Thats it.
I've also made another action the same as above but only processes when the input value changes. I'll add them to the custom actions forum.