[Exim] smarthost and smtp gateway

Situation:

Single exchange server & exim on a high quality Linux box. I'd like to use
exim as the smart host for the exchange server and have exim handle incoming
SMTP requests - passing them on to the exchange server after SMTP time spam
& virus detection. Is it possible to do this with one exim instance? I've
looked for example configurations but have come up empty. Thanks for any
input..