Selection tools


I have a show coming up and I have a led matrix. for a effect I need to make a star drape effect.
I would like to setup new groups. Is there a way to record a random group with an offset. I use the selection tools and get the look I am after but when I save the group it is all the fixtures. I have tried selected and non selected. Or is there a way I can just give them different intensity values and suck just those fixtures into a group. It is the color web 250 so I am thinking to do that they need to be induvial fixtures rather then a multipart.

Cheers mike