I have a large data set and running macro A on it will take a very long time. Usually I will create 12 Excel instances and assign each instances to one processor. Then kick off macro A in every 12 instances. This takes a lot manual work because there are several inputs that user need to enter when kicking off macro A.

I have attempted to create one master macro that will tell each of 12 instances to kick off macro A and pick the necessary input from a predetermine area. The problem I have encountered now is that when I tell instance 1 to run macro A, it will start running macro A. I cannot immediately tell instance 2 to run macro A until instance 1's macro A is finished. My goal is to have all 12 instance to macro A simultaneously. I could do it manually by going to each instance and hit the macro button. But there is a way for me to do it in one master macro?