[Exim] filters and \N

Should I be able to use a \N pair to enclose *any* text in a filter object?
exim moans if there is a space char somewhere between them:

[root@server1 exim]# ./bin/exim -bf userfilters/test
Warning: no message headers read
Sender    = root@???
Recipient = root@???
Testing Exim filter file userfilters/test

Filter error: "and" or "or" or "then" expected near line 4 of filter file, but found "nigeria\N"


[root@server1 exim]# cat userfilters/test
#Exim filter <dont ever delete this line>
if
$message_body contains \N nigeria\N
then
seen finish
endif


TIA
Terry.