[ns] changing the routing parameter?

[<mahesh@cs.iitm.ernet.in>]

Dear seniors,

	i'm working in multicast routing. i'm new to ns. It seems that the
routing protocol(ofcourse multicast routing protocol) uses the hop count
as a parameter. 
is that true? 
if it is, what modifications(which files) to
be done in order to change the routing parameter(to RTTdelay etc.) 
if it is false, how to tell the routing protocol to use a specific routing
parameter. 

thanks in advance

bye...................sincearly urs
                       mahesh.