CafeTran

It's quite easy to exclude text in MS-Word documents from being presented in CafeTran Espresso 2019: just hide it.

The opposite scenario, to translate only the text that has been marked (e.g. by colour), requires some more steps. However, there is this nice solution: TransTools

http://www.translatortools.net/word-hideunhide.html

Note that TransTools only work in the Windows version of MS-Word!