Trixbox - ATA adaptor - Nortel Norstar ICS

Hello everybody.

I installed trixbox at work a few months ago and I am very happy with it.
The only thing that bugs me is that we are still using our old Nortel Norstar Compact ICS system.

I installed a Linksys PAP-2T ATA adaptor between Trixbox 2.6.1.13 and my Norstar system, we can use 2 VOIP lines from the Nortel phones, passing through the ATA adaptor, it was easy to make it possible to make outbound calls from the Nortel phones through VOIP lines.

But now, we need to make it possible to receive calls from the voip system on these Nortel phones. I tried a few things from what i've read on the web, but everytime I dial the custom extension, for some reason, the call is dropped.

here is what i've tried:
Let's say one of my ATA's extension is 333, and the extension # I want to dial on the nortel system is 505
So, the idea would be to redirect the call to extension 333, then wait one second or so, then dial the digits 505

I added a CUSTOM extension in the extension tab of trixbox, in the dial box, i put something like:
SIP/333,,505 OR SIP/333(ww505) OR SIP/333ww505@pstn OR SIP/333ww505

In the config file editor, in the extensions_custom.conf

include => from-internal-ABCDEF1234
[from-internal-ABCDEF1234]
; exten => 353,1,Dial(SIP/333wwwwwww505@pstn)
exten => 353,1,Dial(SIP//333)
exten => 353,2,wait(3)
exten => 353,3,Dial(SIP//505)
-----------------------------------OR
;[from-internal-ABCDEF1234]
;exten => 353,s,Dial(Local/333@local-local,D(ww505))
;exten => 353,2,Hangup
-------------------------------OR
;exten => 555,1,Dial(Local/333@local)
;exten => 555,2,wait(2)
;exten => 555,3,SendDTMF(505,1000) ;

Does anybody has an idea of somethign Icould try !?!

thanks alot !