Make a box in autoshapes, type the text on the box, hyperlink to the box
(not to the text - this might be tricky the first time or two).
If you don't want the box to show, format the box with no line and the same
color
as the background color (or make it 99% transparent).
One problem will be lining up the box with the surrounding text (if this
is played on different machines). Saving fonts will definitely help on this
one.
Another method might be to put a 99% transparent box over the text and
link to that, but you might have the same problem with lining up the text
(but not realize it),
also sometimes it's easy to mess up the order of what's on top of what (or
who as the case might be).