While the official reply was that it cannot be done, but I found another way to doing this and sharing it here just in case someone else needs it. I am using a tool from Microsoft that can capture pcaps and allows user to set filters based on process ids. [http://www.microsoft.com/en-us/download ... px?id=4865]
So in my workflow, I am executing a sandboxed program, then use start.exe /listpids http://www.sandboxie.com/?StartCommandLine to find process-ids and then automatically use them to trigger Microsoft's nmcap.exe utility mentioned above to capture packets from certain processes. This way I can monitor traffic from PIDs running in a particular box within sandboxie, isolated from other boxes that may be running.
If MS could do it, I am sure Sandboxie team could do it too
and make it an awesome feature 
Thanks.
