map different local port to different external port

diff --git a/src/org/chris/portmapper/PortMapperCli.java b/src/org/chris/portmapper/PortMapperCli.java
index 641ab0b..cea8acd 100644
--- a/src/org/chris/portmapper/PortMapperCli.java
+++ b/src/org/chris/portmapper/PortMapperCli.java
@@ -301,10 +301,24 @@
            final String[] optionValues) throws RouterException {

        final String remoteHost = null;
-       final String internalClient = optionValues[0];
-       final int internalPort = Integer.parseInt(optionValues[1]);
-       final int externalPort = Integer.parseInt(optionValues[2]);
-       final Protocol protocol = Protocol.valueOf(optionValues[3]);
+       String internalClient = null;
+       int indexstart = 0;
+
+       if (optionValues.length == 4)
+       {
+               internalClient = optionValues[0];
+       } else if (optionValues.length == 3){
+               internalClient = router.getLocalHostAddress();
+               indexstart = 1;
+       } else {
+               logger.error("Invalid number of arguments for option "
+                       + ADD_OPTION);
+               return;
+       }
+
+       final int internalPort = Integer.parseInt(optionValues[1 - indexstart]);
+       final int externalPort = Integer.parseInt(optionValues[2 - indexstart]);
+       final Protocol protocol = Protocol.valueOf(optionValues[3 - indexstart]);

        final String description = "PortMapper " + protocol + "/"
                + internalClient + ":" + internalPort;