Just found an app that might suit your needs. I suggest you check it out.
Ok, I just tried this app out, and it does exactly what you need.
It comes packed with an app alt, ctrl, tab and del buttons that let you alt+tab among other things.
I didn't see MPC-HC in the server setup, but that's not a problem as you can configure your own profiles with specific commands.
Fair warning, it's a bit on the slow side (seems to be a port of a winmo app), but I'm sure it'll get better with time and updates. It's a very polished Remote app for android and it even comes with drivers for a G-sensor controller to play games with (use android as wii-mote/controller).
This app defenitly rocks.