Cumulative calculations for two columns in a table to be placed in the footer

[noelr]

I am trying to prepare a template document for invoicing purposes using tables with five columns.

The template has to facilitate the following in the columns.;

Date, item number, narrative of work, monetary amount, monetary amount.

I need to find a way to 'tot up' or calculate the figures in the footer of each of the last two columns on each page. The documents can be very long (up to 100 pages sometimes) and the figures would have to increase as the invoice does, i.e. a cumulative total for all the pages that have gone before being added to the figures in the columns on that page.

I've seen it done before using VBA but don't know how to replicate it.

Also if not VBA is there another way of getting word to do calculations that I might explore?