ok, I don't see a lot of information on that TV but it looks like most Hitachi projection TV's have discrete inputs. You want macros that look like this:

Watch TV:
Power on TV
Power on Sat
Power off DVD
Pause
Switch TV to Video 1(This should be in the command list for your tv)

Watch DVD:
Power on TV
Power off sat
Power on DVD
Pause
Switch TV to Video 2

The length of your pause will depend on your tv. You are just trying to give it enough time to be turned on and ready to accept the next command.

I should have asked you for you dvd model information as well but it may be trickier to turn that on and off. See if there are separate power-on and power-off commands for your DVD.