[ddouglass]

Hoster and Microstudio are two separate stand-alone programs. Hoster is for doing Karaoke shows where you use a separate/second monitor/TV for the singers to see the lyrics display.
Microstudio's purpose is not to do shows, but for working with music files both Karaoke and standard audio CDs. You can use it to record your own voice with or without music, import songs to the hard drive, burn your own custom CDs, and many more features.
As far as plugging in from your Mixer to PC Mic input, besure the impedence matches what the laptop is looking for or it will not sound good and may even damage your laptop's sound card. I would definately do some research on the internet to find out how to set it up.