If you are creating a message, you can specify an argument and the code to replace the string to be internationalized in the Message Format Arguments dialog box.
To enter substitution parameters for a message format:
A series of parameters, beginning with 0, is added to the text field.
The value is added to the parameter in the Arguments text field. To remove an argument, select it in the Arguments text field and click Remove.
The arguments you supply are added appended to the end of the message format:
java.util.MessageFormat.format(java.util.ResourceBundle.getBundle("bundlename").getString(new Object[] {arg0, arg1,...});)
See the documentation for java.text.MessageFormat for more information on using localized strings with parameters.