Can a MACRO be written to run repetitively until cells equals zero?

I have twenty-seven different customers who are requesting to alter their contractual entitlements to electric power in kilowatt hours over the course of a year. It is an exchange in which I am required to balance their requests to the total of preexisting contractual entitlements for all customers each month and the total of each customer’s individual prexisting entitlement for the year. I have two calculations which I have built into a MACRO that seems to get me closer to balance each time I run them however I would like to embed that MACRO into another MACRO that would test twelve different cell values after my calculation MACRO runs and then repeat the calculation MACRO until those twelve cells equal zero. I would really appreciate anyone who may have done something similar and has an example.

Thanks,

JP