SuperDuper! as backup/restore program?

[rcatrambone]

I just purchased SuperDuper! but am concerned that I can't do with it what I want to do. I want to use SD! as a backup program in the following way:

After working at the office, I want to transfer my files (documents) from my office computer's hard drive to my external hard drive (a firewire device) in a "smart" way (i.e., have just the files that have been changed get copied to my external hard drive). All the files of interest are in a single folder on my computer's hard drive and on a single folder on the external hard drive. I want to carry the external drive home, hook it up to my home computer, and transfer the files to my home computer's hard drive, again in a "smart" way. The next morning, before I head to work, I want to transfer the files from my home computer's hard drive to my external hard drive, again, not surprisingly, in a "smart" way. And so on.

I am not interested (right now) in cloning or making bootable cds, etc. All I want to do is to be able to take files in-between work and home via my external hard drive and to keep things up-to-date in a "smart" way rather than having to copy all files each time.

I can't figure out how to make SD! do this; I can't get it to choose a particular folder or choose the computer's hard drive as the destination. I bought SD! based on the recommendation from an Apple discussion group although the responder to my question might have misunderstood my goals (or I explained them poorly....).

If SD! can do what I want, would you tell me how to do it? Thanks.