help with encodings

[greg]

Hi
never felt so stupid before

I have a file which is basically ascii except for few hexFA (250) bytes
(so if you look at it in notepad it looks readable and those 250 displayed
like ú
the reason they use them as escapes for some sort of compression
ok
if I read this file in using StreamReader all those special guys disappear
fine i thought I am still smart so I read it in as byte array
of course after that I still need to convert it to string to use c# IndexOf
on that stupid ú
UTF8 encoding throws it out
Ascii (when converting to chars[] makes it ?

question
how do i get nice c# String which will still contain something out of band
for ascii chars
but still be a c# String (which we all love and know or at least that's what
I always thought)

Thanks
GSL