Pasting text and keeping the destinations attributes?

I format a document in CDx5, and send a proof to the client... the client sends back extensive changes in text format. I want to copy the unformatted changes, and paste them so as to replace the original "formatted" text... AND I want the newly pasted text to retain the formatting of the text it's replacing. MS Word can do this... how do I do it in CDx5???

HELP :o)