ls -1 | sed "s/\(.*\).step2.xml1/move & \1.xml/" | cmd - for batch renaming files. Refer this.

Installing a toolkit with Unix utilities is a must (until PowerShell Monad is available). I recommend this and this. If you use the sourceforge one, the advantage is that the commands are a direct port - much faster. Standard approach is to just dump all these files into a Utils folder which is in your computer PATH. Then all your "cmd" shell windows will support these commands. "grep", "sed" are really useful from this bundle.

When you use replaceAll in Java, you cannot use a "$" or a "\" in the replacement String.

It throws a java.lang.IndexOutOfBoundsException: No group XX exception. The solution is here. The "$" and the "\" in the replacement string have to be delimited before being sent in to the Regex parser.