Theory only; but this shouldn't be too hard.
Its all about the horizontal refresh rate on the monitor, Your PC is 30ish, standard res monitors are 15 and a medium res monitor is about 22khz (I think).
So, whatever software you were going to use to force your g400 to output at 15khz you should be able to force it to send the signal out at 22khz instead and she will be a dingo.
Oh, you might want to confirm exactly what refresh rate medimu res monitors actually want, those thing are not cheap. Lucky you !