asterisk users - Jan 2006 - Extensions for in-bound faxes w/o properly-provisioned T1.

Hey, all.  I've got a non-PRI T1 that doesn't do DID
"correctly:" I can't
get the DID from the proper variables, and, instead, I direct it based on
the four "least valuable" DTMF digits dialed by the T1 for in-bound
calls.

Which really works pretty well; Asterisk plugs them quite nicely into
${EXTEN}.  Unless, that is, ${EXTEN} gets over-ridden when it's directed
to the Fax extension.

I still see the DTMF digits:

Jan 22 01:03:20 DEBUG[11154] chan_zap.c: DTMF digit: 1 on Zap/1-1
Jan 22 01:03:20 DEBUG[11154] chan_zap.c: DTMF digit: 6 on Zap/1-1
Jan 22 01:03:20 DEBUG[11154] chan_zap.c: DTMF digit: 2 on Zap/1-1
Jan 22 01:03:20 DEBUG[11154] chan_zap.c: DTMF digit: 5 on Zap/1-1
Jan 22 01:03:21 DEBUG[11154] chan_zap.c: DTMF digit: f on Zap/1-1


But I don't see any graceful way to import that information when things
like ${DNID} and ${RDNIS} don't work.  I could tweak chan_zap.c to dump
them to a temporary file (or perhaps even cram them into ${DNID}, since
it's pretty empty just now), but that ain't exactly graceful.

So: any suggestions?

Thanks!

-Ken