Got it.
I see that the interrupt vectors are declared in the M9S12XEP100.inc file, so that is how you could declare them without an ORG statement. I am able to get my test program to work with relocatable assembler. Now I have to try and get the RTI interrupt to be handled by XGATE. I'll try the sample dual core example and see if I can figure how to work my code into it.
Thanks so much for your help Ladislav.