[exim] RHS expansion a la mailertable

Colleagues,

In mailertable (sendmail) I can write
.old-company.com = smtp:%1.new-company.com

In the CGP routing table I can write:
*.old-company.com = *.new-company.com

How do I achieve the same RHS expansion in an exim router (in route_data)?

The simplest way would be to enumerate all the domains like

foo.old-company.com: foo.new-company.com
bar.old-company.com: bar.new-company.com
...
baz.old-company.com: baz.new-company.com

But can this be done with just one line?

Thanks a lot for any input.

--
Victor Sudakov, VAS4-RIPE, VAS47-RIPN
sip:sudakov@???