krb4 confusion serving multiple domains

[Len Burns <lenb@sasquatch.com>]

Good evening,

I have the feeling this is not complicated, but I am failing to figure
out how to do it.  I am running Heimdal as a part of NetBSD-1.5.1
i386, serving krb4 and krb5 clients happily.  Now, I have a need to
authenticate clients from a second domain using krb4.  I have 2 hosts
named www.bla.com and www.bla2.com.  What I am unclear on, is what I
need in my krb5.conf file on my kdc so that host/www.bla.com is found
when authenticating from www.bla.com and host/www.bla2.com is selected
when authenticating from www.bla2.com.  I have dug through the
krb5_425_conv_principal man page, and am clearly not quite grasping
how to do this.  Pointers would be greatly appreciate.  TIA

-Len