Skype for Business (Lync) and IP Office SIP Integration

[joestar]

I have a client with a Skype for Business 2019 Server and I am trying to integrate this using SIP with their IP Office 9.0. There are a couple of articles about how to do this using SIP URI. I have attached one but it was only somewhere helpful. I have successfully been able to add the SfB server as an additional SIP Line and I can use an Incoming Call Route to get any calls from Skype to go to a specific extension. I have also been able to use the Incoming call route to take all incoming calls from the SfB server and send them to a short code which routes to a specific cell phone number. However, what I am unable to do is take the number that the user dialed using SfB client and pass that through to the IP Office and then to the SIP trunk to call out. Does anyone have experience with this, or just in general with taking calls from a SIP line and passing the number out to a SIP Line Trunk? I have also not started to work on routing incoming calls to the SfB client but ideally would like it to simultaneously ring the IPO and SfB extension (possibly I could use twinning somehow).