I frequently write emails in languages other than English and I have
found that the way to add accent marks and the other non US characters
(ie ñ ¿ ¡ etc) is to go to the control panel and then add the language
you want. I use Spanish (Spain) and have found that I am also able to
insert all the characters needed to type in Italian, French and
Portuguese. It just takes a little getting used to before you know
what keys to press.

You could also probably buy a keyboard in a Spanish speaking country;
they have the needed keys (keyboards in Italy have them too).

For me the fastest way it to change the keyboard setting as I
described. You do not need any updates to word or outlook, the change
is done on the OS level and thus available in every app. Once done you
can set up the computer to allow you to toggle between the two setups
with a simple keyboard shortcut (I think the default it ALT SHIFT,
that is what mine is anyway)