I exported a sim with the in game tool, so my sim now exists as a sims3pack and also is in the game's library file. I did not save to the CAS bin, so I do not have a .sim file. Taking the sim back into CAS with cheats does not give the option to save to the CAS bin. Is it possible to extract the .sim file from the sims3pack, or is there another way to get this file format for this sim? Thanks!

MultiInstaller will extract to *.package and all you'll have to do is to manually rename it to *.sim. Windows will give you a warning first, you just have to agree to the extension name change and then your Sim can be placed in SavedSims.

Thanks Don, I very much appreciate your help. I thought I could do it the way you suggested, but I wanted confirmation. You just saved my computer from me having a go at it with a wrench, which would not have ended well for it or me. Thanks again!