CREATE PART WITHIN ANOTHER PART OR ASSEMBLY

I have attached a jpg and prt file to show what I would like to do.  I am basically cutting out designs from foam.  I would like to be able to draw a sketch of the design onto the representative base material and then create a part with the cutout (which would be linked to the sketch) and a part of the actual final part. (split into two parts basically).   I could also see possibly making an assembly with the two parts and making a cut with the shape into the base material....the only thing is that i want to pattern these cutouts and show some of the positions with the shape still sitting inside and some positions with the shape removed.  There might be multiple ways to do this but I'm struggling with any of them.  Hope this makes sense.  Thanks for any suggestions.

SolidworksParts And Features