You can't unless you have greek fonts. You can get them, but I don't know how.

This tool looks promising
http://users.ox.ac.uk/~tayl0010/polytonic-greek-inputter.html

found it linked off of this website
Greek Fonts

Might find this useful;
http://www.kypros.org/cgi-bin/lexicon

I think it might be a lost cause.

I tried using the converter that Deckard provided to put a word that I know through the translator that Vide provided and it didn't translate it right. I will have to just skip over those portions of the text. Fortunately they are used sparingly. I appreciate your help though.

I have been trying to learn more of it for the same reason...Now I have a real good dictionary, Greek Bible and Bible Greek dictionary... It is interesting, but I am too old to learn it well now...I am sort of getting to where I can sound out words, and some are not so different... I saw some yogurt in my refrigerater, Oikos, was written on it...I closed the door...I know that word I said: house...Which we know through oikonomos, I think is the spelling: House management: Economy...

On that translator click on "Greek Letters". It looks like there are a whole bunch of additional accents involved so if its not exactly right the right word won't come out of the Vide's translator.

You might also getting one line of the the Greek text exactly right and then googling that line in quotes and you might run across English transaltions. That's a bit of work but it might be worth it if you're really interested in the text.

is there a particular phrase or word you are looking for. describe the letters you do recognize and the ones you do not..

There were some particular words and phrases that prompted me to write this post, but Copleston uses Greek language throughout the book.

I have a book like that on ancient philosophy..

Copleston generally follows the accepted methods of citing Greek and Roman authors; these are found in the footnote information he provides.

For example, he will cite the critical edition of Aristotle by its Bekker number (for example, Metaph A 987b 1-3) rather than a page number from a particular edition or translation. These standard "page" references are usually provided along with any scholarly translation, usually to the side of the text.

For many classical authors, the complete original text can be found at Perseus Digital Library, which provides a handy look up function on the same page as the text:

Greek and Roman Materials

Places such as the IPL or Open Library will usually have translations of the major philosophers' works (with standard references); however, the regrettable US copyright law (thanks to Mickey Mouse) often prevents the more current translations from being offered. In any case, one should remember that translations of the same text may differ significantly, especially with philosophical works.

As someone that is working through there fourth semester of Attic Greek, I can say that it would be a waste of time to try working with the Greek text in Copleston. The little that you may gain by doing so, would take far too much effort on your part. A good dictionary and a good grammar would not be enough to get through--you also need to know how to use them as well. Even just to read a few lines here and there of Greek, I would recommend taking a a series of classes on the Ancient Greek language.

Unfortunately, there are really no good resources on the net for ancient Greek/English translations. The things that are up on the net are greatly inaccurate at best.