Merge Fields in Writer...Can they be used to calculate?

I have a working split database. That is saving itemized monthly expenses. I am creating a report that requires graphs, pictures, and annual figures.

So I created a Writer Merge file that is getting monthly data from the database table. Now my issue is how do I convert this monthly item into yearly on my writer document. Below is a sample!

<Mo_Exp1> * 12 = Yr_Exp1 <<<<< Where and How do I do this in the writer side, so merge doc will produce the result of yearly expense for that item.

Hello,

Why do it in Writer? Just create the total in a Query and send that.