I use Unix more the DOS and so when I use DOS I find myself typing Unix commands. Clear was the worst for me. I would always type clear instead of cls. So you can add some Unix commands to DOS by following the steps below.

1. Go to the System 32 folder in C:\Windows.
2. Make a batch file with the name of the Command you want (such as clear).
3. Inside the batch file type the equivent DOS command(s).
4. Save and exit.

Now you should be able to excute this new batch file no matter where you are in DOS just by typing the name of the Batch File.

I also think you could make applications that could have the same functions. Just put them in the System 32 folder. I however reccommend not deleting any files in this folder because its crucial to Windows operation.

That's why I've used 4dos and 4nt for years. I like the command prompt and if 4dos doesn't have it, you can set an alias for any command you like.