Is there any way to declare regexp using mxj?

I am trying convert the xray.dynamicexpr file but i am not sure how to translate it from javascript into java:

Is there any way to declare regexp using mxj?
I am trying convert the xray.dynamicexpr file but i am not sure how to translate it from javascript into java:
var re = new RegExp("\$0");
re.compile("\$" + i);

regexp-using-java

http://java.sun.com/docs/books/tutorial/essential/regex/

regexp using Java