Translate site word and not interface words

I don’t get this. All I want is to translate the theme words and not the WP interface words. I have no interest in having WP in another language than English but my site needs to be translated for my local audience, so how do I do that? Using this plugin changes ALL text, both in the site and in the WP interface!

http://wordpress.org/extend/plugins/codestyling-localization/