[plug] trouble with searching for non-ascii characters in a text file

[David Buddrige]

Hi all, 

I have some html files that contain odd [non-ascii] characters here and 
there.  The web-browser displays them as "?" in the html page.  My text 
editor uses another character to represent that particular character.  I 
want to find out how to determine what exact hexadecimal value that 
character evaluates to, and then how to grep on that hex-value - rather than 
its ascii equivilent.  is this possible? 

thanks 

David.