Microvellum Community

modifying cabs

I am a new user of MV, about 3 weeks.
I know of some modifications that you can do on cabinets, but I was trying to draw a Credenza and can't seem to find the correct modifications to get what I wanted. 
I am doing a one cabinet unit that is 5' long with 4 doors and 3 drawers above.  There is a middle division in the bottom part of the cabinet.  I can't seem to find the correct cabinet in the library to modify.
Any ideas of where or how to make some of these modifications or what cabinet to modify?
Thanks