Adjusting configuration options during port installation?

[Matt Singerman]

Hi all,

I am installing an upgrade to the Cyrus email server.  Our existing
email boxes are in a database format that is no longer used by Cyrus;
however, there is a configuration option which will instruct the new
version to use the old database format.  They are

--with-mboxlist-db=berkeley and --with-seen-db=flat

Is there a way to tell the FreeBSD port of Cyrus to use these options?
 I am not extremely familiar with the ports system.

Thanks,

Matt