I need to solve the following problem in Solver. To me, the setup in Solver
should be straightforward, but I am not getting the correct answer or really
any answer.

Simplified Example: In Column A, I have a list of numbers; in Column B, the
respective percentage-of-totals; and in Column C, the percentages from Column
B rounded to the thousandths place (3 digits) -- so that Columns A & C are,
for example:

A C
1 3.70%
2 7.40%
3 11.10%
4 14.80%
3 11.10%
5 18.50%
6 22.20%
3 11.10%

The total sum of the values in Column C = 99.90%. I would like to change
the value of one cell in Column A -- for example, the value in A1 (which is
1) -- to come as close as possible to a total of 100% in Column C.

I have set the Target Cell as a separate cell which is the absolute value of
the difference between the totals of Columns B & C and set it Equal To 'Min'.
'By Changing Cells' is set to cell $A$1. I have tried different
combinations of constraints ($A$1 is an integer, = 0, <=100) and tried using
no constraints. However, I still get basically no answer. (It just gives me
whatever I started with.)

Any help is appreciated -- thanks.