[exim] mysql_servers for multiple servers

My reading of the spec/book is that mysql_servers is a global ("main
configuration") option, so any MySQL queries are going to look, in
order, at the same list of hosts specified therein.

I have a couple of unrelated MySQL queries that I want to do to
different MySQL servers. I'd rather avoid the attempted queries of
the wrong servers. Is there any per-query or per-router or per-ACL or
per-whatever way of specifying the MySQL server info?