Well internet streams can be rtsp or something else. If you really want everything to go to mpc hc take your existing rule and take out the file type or file name party. It should just be
rule video="true" player="mpc-hc" /rule
The only downside to that is that PVR will break, so if you are using PVR you will need to ignore everything I just said

To use PVR (ie - what I call the more "hacky" way) then leave all your file type and file name rules defined
and add one more rule with internetstreams="true" and mpc hc as the player