Your code is small, clean and readable and in my eyes it is well optimised code.
If you are in need of different upper and lower bounds for your random numbers I suggest to implement the following :
Private Function RandomInteger(Lowerbound As Integer, Upperbound As Integer) As Integer
RandomInteger = Int((Upperbound - Lowerbound + 1) * Rnd + Lowerbound)
It adds a little more code and slightly decreases performance, but you could use it in other parts of your project and it's more readable.
Now I do not have much experience in VB6.0 but everywhere I looked they call the
I'm not sure if this is a mistake or if the compiler accepts both ways?