The kind folks at the Unicode Consortium have acted as the referees for the font world by creating a consistent system by which a variety of fonts may represent a variety of characters and symbols in a uniform way. As long as a computer has an up-to-date unicode font, it should be able to display text written in unicode, even if it does not have that same font in which the text was written.
The trouble lies in actually typing the characters because our keyboards are often set for the typical Latin fonts (e.g. English, French, German, etc...). To type unicode characters beyond those on your keyboard, one needs to have an alternate (digital) keyboard layout available. Stefan Hagel has created a program called Multi Key which works well in Microsoft Word for a variety of languages germane to TC (Greek, Hebrew, Syriac, Armenian, Ethiopic, Gothic, etc...). “But,” you say, “I really want to type in Coptic!” Donald Mastronarde has created a keyboard layout which may be used with greatest success in Microsoft Notepad to input Coptic characters (some, like ϭ, will not show in Microsoft Word).
Interested persons will probably want to acquire the New Athena Unicode font (which has encoding for the biblical languages) and may want to install the Arial Unicode MS font (which, though massive in size, has encoding for just about everything).