at nobody answering the question.
If you want to mute a sound, you can do so to a particular group or a sound. You do that by clicking the letter all the way to the left of the group, or the sound number all the way to the left of the sound.
As far a recording a mute, the short answer is you really can't. You have to cut, paste, and erase the sound. For instance, if you want the same drum pattern to play, but want the hi hats to drop out, you have to cut and paste the pattern, then manually erase the hi hats.
This is one of the downsides of the Maschine. It's not good for sequencing. I recommend using another program for sequencing. Just go to file and export files (make sure loop optimization is turned on) and you can export each individual sound, or just the groups. From there, you can load the waves into a program better suited for sequencing. Popular programs that people use are Garage Band, Logic, Fruity Loops, Pro Tools, and Abelton. There are plenty more also. I'm not sure if you are familiar with any of these, but if so I recommend using one for sequencing, if not, I recommend learning one.