[exim] can "dnslists =" refer to an external list/lookup?

hi all,

i use

dnslists = f.q.d.n : a.b.c.d : ...

in my check of various RBLs. no problem.

is it possible, though, to specify an external source, e.g. a named
list/lookup, for the LIST of dnslists?

any variation i've tried, e.g.

dnslists = +some_named_list

complains about 'unknown data' in dnslists ... :-/

the spec, and the google examples i've found, seem only to refer to literal
domains/ip's.

my _goal_ is to be able to check DIFFERENT lists of RBLs for different domains,
prefereably user -- or at least domain 'owner' -- specified.

thanks as always!

cheers,

richard