VBScript - How to Generate a Random Number, then an If-Statement to Use this Number to Pick an Option

You need randomize and rnd.
int(rnd * n) + 1 evaluates to an integer number between 1 and n.
And you might use select case... here as well, try this:

dim r
randomize
r = int(rnd*10) + 1
select case r
    case 2
        '... 

    case 7
        '... 

end select

And If you would rand from min to max:

Dim max,min,rand
max=54
min=23
Randomize
rand = Int((max-min+1)*Rnd+min)
WScript.Echo rand