Generate "n" random numbers between a and b to reach desired average in m rows

Hi

Suppose in column" Z" with" 200" rows, are my optimal averages
Now I want  a macro that generate " n" integers in  (a,b) randomly (n<=20)so that difference between average of numbers  generated with

optimal average is in (-0.15,+0.15). Example: Z1:optimal average1=5.5 Z2:optimal average2=5.3

Z200:optimal average200=6.3
n=8
a=1; b=10
numbers of generated:
A1:H1)5-9-4-3-7-4-9-3
A2:H2)10-7-3-2-5-4-3-9
.
.
.
A200:H200)4-8-9-6-6-6-10-2