Mac & PC application that listens to a SIP account

The listener will connect to a sip account and when a call comes in it will pop up with an accept button and open to a url in the default browser with the CallerID at the end. The call will be answered on an external phone or softphone - this software DOES NOT need to deal with the voice elements of the call - just trigger the url to open the CRM page or similar when a call comes in. It will need a preferences screen with Settings: Label - Name Of account Register Name - SIP Settings User Name - SIP Settings Password - SIP Settings SIP Server - SIP Settings SIP Server Port - SIP Settings Outbound Proxy Server - SIP Settings Outbound Proxy Server Port - SIP Settings URL to open on call (with %E) at the end which will be the number formatted like this +12345678909 - for example - [login to view URL] (where 0330... is the full international number) Please confirm you have SIP experience and can do this in a timely manner - I have already been let down by one coder and NEED this URGENTLY!!!