[exim] domain lists in retry rules?

I have a half-dozen domains I secondary for in a 'relay.domains' file,
which gets pulled into a relay_domains domainlist, and I want to hang
on to those for a couple of weeks, but mail to my other domains can be
bounced sooner if there are delivery problems.

Very simple question: is there any way to specify a domain list for the
left-hand side of a retry rule, to save duplicating this data? Or is there
a technical reason why that won't work?

Thanks!

--
Rasputin :: Jack of All Trades - Master of Nuns