Display of "N" in cumulative meta-analysis

Hi

I have found that when creating the forest plot for a cumulative meta-analysis (binary outcome) the program adds up all four columns when calculating "N" - this double counting means that not only the number of patients included in the studies but also the numbers of patients experiencing an event are included in the figure.

I have been using a graphics program to edit this column in the plot but I wondered if there was an easy way to stop this happening in the first place?

Jonathan