asterisk users - Jun 2005 - avm c2 correct configuration for two p2p lines

I have an asterisk box connected to two isdn lines via an AVM c2 card,
the ISDN boxes have the 0227006XXX and 0227007XXX numbers, and are
configured both p2p, with the first one as file-leader.
(I don't know if file-leader is the correct term, it's a literal
translation from the italian term "capofila", in other words 
0227006XXX is our "real" number, and when the 2 B channels are both
used
it should forward the call to the second line)

What's the correct configuration for the capi channel/driver ?

this is my current :

/etc/capi.conf

# card  file    proto   io      irq     mem     cardnr  options
c2      c2.bin  DSS1    -       -       -       1       p2p
c2      -       DSS1    -       -       -       2

/etc/asterisk/capi.conf 
(surely wrong, it refers to a previous conf as two separate lines)

[general]
nationalprefix=0
internationalprefix=0039
rxgain=0.8
txgain=0.8

[interfaces]
msn=0227006XXX
incomingmsn=*
controller=1
softdtmf=1
context=incoming
echosquelch=1
mode=immediate
callgroup=1
devices=2

msn=0227007XXX
incomingmsn=*
controller=2
softdtmf=1
context=incoming
echosquelch=1
mode=immediate
callgroup=1
devices=2

Sorry if it's a basic question, but I can't find a detailed and complete
example googling, and being the *box a production machine I can't
neither procede with "try and see if it works" method.