[ns] Add new global parameters for Routing Protocol

Hi,

I'm modifying the AODV protocol implementation in NS2 to add certain
features, and I need to set some parameters for AODV routing (not
node-specific). So, basically I need to define these parameters in such a
manner that I can set these through the simulation tcl scripts.
How can I define these parameters? How can I set these parameters through
my tcl simulation script?

Regards,
Vighnesh