To view Office files within a program running on the Windows side, you will need to install a viewer for Office files on the Windows side. Neither the operating system nor any of the file managers has built-in support for viewing Office files, so it has to come from an extra component, whether we're talking about Windows Explorer, Opus, or anything else.
As far as I am aware, your options are to install either MS Office or QuickViewPlus on the Windows side. The viewers provided by those two options are different, so it you choose QuickViewPlus, be sure to try it out first to see if it displays things as you require.
(In theory, OpenOffice/LibreOffice also installs a viewer, but its viewer has not worked properly in anything for years so it's probably not worth the time to try it.)