[Freeswitch-users] Adding an info digit to sip from header

[Josh Forman]

I'm trying to edit the sip headers to make the from field look like  
this:

From: <sip:SOMENUMBER at SOMEIP:5060;isup-oli=27>;tag=gK0a00d6ea.

I know that to read that data on an incoming sip message it is in $ 
{sip_from_params}, but how can I add the ;isup-oli=27 part on an  
outgoing message?

Thanks

Josh