Two stream in two cfiles

Hi all, probably the last question of the year :wink:
I have a USRP v1 with 2 rfx900 daughterboard. Im trying to listen on two
frequencies (one for each DB) and save the corresponding data in two
differrent cfile. That at the same time. Hence i tried to modify the
uspr_rx_cfile.py using trick from multi_file.py
But i dont really know how to configure the mux (seams it should be
0x32103210 but not sure). Moreover how do i deal with the number of
channel when creating the source.And finally, how can i connect a stream
from one subdevice to the first cfile output and the second stream from
the other subdevice to the second cfile? Do i need a
interleaver/deinterleaver?
Thanks for your precious help.
Best  wishes for 2010 to all of you, regards,Â
sylvain