Specifying port in 'forwarders' directive?

[Brian Thomas]

It doesn't look like there's any way to specify an address/port combination
in the 'forwarders' directive, is this correct? Is there a specific
reason for this, besides "Why would you want to?"  :)

I'm trying to set up a test environment and it would be useful to
be able to do this. I'm a little surprised that since you can set up
BIND to *listen* on any port you want, and can specify ports in things like
dig and nslookup, that you can't specify one in the forwarders directive.

Brian