TCC (Take Command Console) is the new name for 4NT, which is now free in its basic (LE) version. I used 4NT for years, and it's a great console replacement for CMD, but until now it wasn't free.
See home page at http://jpsoft.com/tccledes.htm
and the direct download link is at http://jpsoft.com/downloads/v9/tccle.exe
To install, I ran the exe installer, then copied all files and uninstalled it.
By default it writes its settings to C:\Documents and Settings\<user>\Local Settings\Application Data\JPSoft\TCMD.INI, but copying this file to the application's directory made it use the local copy exclusively.
I tested with procmon, and couldn't find any other reason to suspect it's not portable.