It's no problem to have one list subscribed to another, so long as you
avoid loops.  We have a hierarchy of lists for our division, each
department in the division, and each group within each department.
The department lists are subscribers on the division list, the groups
lists on the respective department lists.  Works just fine.
 
Mark R. Williamson, Rice U., Houston TX; [log in to unmask] or @RICEVM1