I have a series of values both positive and negative that I want to change so
that they add up as close as possible to a given value. For example 100000 +
200000 + +300000+ 80000+ -50000 + -250000 I want to change so that they add
up as close as possible to 300000.

The problem is that the only change in value of the cells I want to allow is
to change them to 0 and I am having trouble setting up the constraints to do
that.
I can see that the answer is to change the 80000 to zero to give me the
300000 but how can I get solver to do this?

Thanks, Donna