Hi Lambs,

The syntax is:
{=«Amount1»+«Amount2»}

Assuming you've got your two mergefields, «Amount1» & «Amount2»,
side-by-side, you can create the above by selecting both fields then
pressing Ctrl-F9 to wrap another, empty, field around them. Then, simply
fill in between the field braces so that you've got the above and add
whatever numeric formatting you want. For example:
{=«Amount1»+«Amount2» \# $,0.00}
will give you a dollar & cents result, with a thousands separator, in your
merged output.

Cheers