[Exim] MS-TNEF headers in Exim virus scanning

Hi,
I've been asked to set up a mail virus scanner with Exim. I also heard
whisperings of Exim 4 having "hooks" to attach a mail scanner with.
My concern is that Exim will not be able to unwrap MS-TNEF (or for that
matter, any other type of mime) headers.

Can anyone put my fears to rest, as it may be a better option just to go
for Exiscan or Amavis?

Thanks in advance,

Alex