[exim] Redirect using an Exim filter

Hi all,
I'm having a problem with Exim4 and I cannot resolve it by myself:
I'm trying to obtain from Exim a delivering to different local
accounts of incoming mails fetched thru fetchmail.
I've composed an Exim filter but now I need to let Exim knows that
filter is there. I thought it must be declared in routers section, but
I don't know the commands and keywords to use. What should I do now?
I'm almost a newbie with Exim, so I need a step-by-step help from
those ones that can help me.
Thanks a lot.

Matteo

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