[exim] How to put .forward file commands in exim4.conf

I am beginner Exim user.

I do not have linux account for my virtuals users and I can not create forward file for my virtuals users.

How to put this .forward commands (below) in my exim4.conf ?

# content of the .foward file
if $h_subject: contains "test" then save .maildir/.testFolder.testSubfolder/
elif $h_from: is "not@???" then save .maildir/.SPAM/
endif

Thank's