To get the download version of the game (or the patch for a retail copy) up and running on an offline machine:
Right click on the game in SDC, and choose Archive Application->Selected Application to pack it up without redownloading.
When the archive process finishes, you'll find the .sdc file(s) in C:\Program Files\Stardock\Stardock Central\BACKUP (this path is customizable in SDC's settings so it may vary). Copy the .sdc files along with the SDC installer to the portable media of your choice (CDR, DVDR, USB drive, etc).
On the other computer, install SDC, then double-click the .sdc archive files in explorer to unpack them.