asterisk users - Jul 2006 - How to send a signal via E1/T1 ISDN to asterisk, to ask the call to be moved.

Hi, all
I have an * which receives calls from PSTN and some of them fo to an E1 
where another system is working   (Dialogic Boards).

I need to be able to send a signal to * from the system with the 
Dialogic boards,  preferrably via the E1 so that * knows it has to move 
the call from slot ZAP25 to  SIP/ xxx .

Im thinking to use the manager with a socket connection for this,  but 
would be much cleaner for me if I can send a message via the E1,

has anyone done something similar?
please welcome any ideas for this


PS
(if this sounds familiar,  it's because I'm trying to go arround the 
2b-channel limitation that we discussed earlier on,  where I couldn't 
find a way to tell )