This is a difficult one to explain, so I will provide an example:

a 1
b 2
c 3
d 10
e
f
g
h
i
j 2
k 5

Rows a through c contain a value for a given period, while row d contains a
lump sum for all future periods. Row j is the average of rows a through c
(which I am using as an estimate of future periodic values), while row k is
row d divided by the average calculated in row j (the number of periods
necessary until the lump sum is reached). What I am trying to do is then
repeat the average calculated in row j in rows e through i the number of
times shown in row k (thereby giving me 8 periodic values as opposed to 3
periodic values and one lump sum). Any ideas on how to do this?

Thanks so much for the help.