[Exim] BIG whitelist_from for Spamassassin

Hello All,
I have tried to scan the mailing list for the answer..so forgive me if it is a
dupe.

I have a customer that needs a large whitelist in spamassassin.
I would prefer to have a seperate list than my stock one
(/etc/mail/spamassassin/local.cf).
Does anyone know if I can refer in it an external file? Thanks!

Mark