/* http://es.stackoverflow.com/q/51051/127 */
 
import java.util.regex.Matcher;
 
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String ruta  = "C:\\Archive\\carpeta\\archivo.ej";
		String regex = "^C:\\\\Archive(?:\\\\+|$)";
		String reemp = "E:\\";
		System.out.println("Ruta: " + ruta);
 
		ruta = ruta.replaceFirst(regex, Matcher.quoteReplacement(reemp));
		//escapar caracteres especiales ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
		System.out.println("Reemplazada: " + ruta);
	}
}

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