[exim] Exim include file for routers

Exim users,
Is there a way to include a separate file from within the routers section?
I would like to put the include file before other routers take place,
but am unsure the order that Exim will process it if inside another
file.
Is this possible, and which order will Exim process the routers?

Thanks!

--
Brent Jones
brent@???