Finding and mapping all UTF-8 characters

[deech]

Hi all,
I recently cut-and-pasted large chunks of text into an HTML document.
When I tried to save the document I was warned that it was ISO-Latin
but there were UTF-8 characters in the text.

Is there a way to (1) search for the UTF-8 encoded characters in a
document and (2) map them to a sensible ASCII character?

Thanks ...
-deech