Yes, I do this with BOINCTasks. No problem.
On the remote machine, in the remote_hosts file, you have to add the external IP address of the local machine (not the 192.168.x.x it uses for the internal lan).
And on the remote router, you will need to use port forwarding. If you have more than one machine there, you will need to assign unique external ports in the router. But the internal numbers need to be 31416.