Combining rootfiles with different weights

   Dear Rooters,

                      I am trying to combine events from two root files. One corresponds to one channel and other to another one. I want to create a cumulative file containing events from both channels in proportion to their crossections. Is it possible to do some jugglery with hadd macro and 
make it to do "weighted addition" or some thing similar??
                                  
                                  Any help will be grately appreciated.

1. Singh LPC, Fermi Lab